Forbid rustdoc warnings in CI (#12420)

* Forbid rustdoc warnings in CI

This commit corrects our handling of rustdoc flags in CI to ensure that
warnings indeed fire. Additionally this changes our fl

Forbid rustdoc warnings in CI (#12420)

* Forbid rustdoc warnings in CI

This commit corrects our handling of rustdoc flags in CI to ensure that
warnings indeed fire. Additionally this changes our flags to pass
`-Dwarnings` to ensure that we have warning-free doc builds when all
features are enabled at least.

There were quite a lot of preexisting issues to fix, so this
additionally goes through and fixes all the warnings that cropped up.

* Update nightly toolchain again

prtest:full

* Update another nightly

* Fix a warning in generated code

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Cranelift: support dynamic contexts in exception-handler lists. (#11321)

In #11285, we realized that Wasm semantics require us to match on
dynamic instances of exception tags, rather than static tag

Cranelift: support dynamic contexts in exception-handler lists. (#11321)

In #11285, we realized that Wasm semantics require us to match on
dynamic instances of exception tags, rather than static tag types. This
fundamentally requires the unwinder to be able to resolve the current
Wasm instance for each Wasm frame on the stack that has any handlers,
and our frame format does not provide this today.

We discussed many options, some of which solve the more general problem
(Wasm vmctx for any frame), but ultimately landed on a notion of
"dynamic context for evaluating tags", specific to Cranelift's
exception-catch metadata; and storing that context and carrying it
through to a place that is named in the unwind metadata. The reasoning
is fairly straightforward: we cannot afford a more general approach that
stores vmctx in every frame (I measured this at 20% overhead for a
recursive-Fibonacci benchmark that is call-intensive); and inlining
means that we may have *multiple* contexts at any given program point,
each associated with a different slice of the handler tags; so we need a
mechanism that, *just for a try-call*, intersperses contexts with tags
(or puts a context on each tag) and stores these somewhere that the
exception-unwind ABI doesn't clobber (e.g., on the stack).

This PR implements "option 4" from that issue, namely, *dynamic
exception contexts*. The idea is that this is the dual to exception
payload: while payload lets the unwinder communicate state *to* the
catching code, context lets the unwinder take state *from* the catching
code that lets it decide whether the tag is a match. Because of
inlining, we need to either associate (optional) context with every tag,
or intersperse context-updates with handler tags. I've opted for the
latter for efficiency at the CLIF level (in most cases there will be
multiple tags per context), though they are isomorphic.

The new tag-matching semantics are: when walking up the stack, upon
reaching a `try_call`, evaluate catch-clauses in listed order. A
`context` clause sets the current context. A `tagN: block(...)` clause
attempts to match the throwing exception against `tagN`, *evaluated in
the current context*, and branches to the named block if it matches. A
`default: block(...)` always branches to the named block.

Note that this lets us assume less about tags than before, and this
particularly manifests in the changes to the inliner. Whereas before,
`tagN` is `tagN` and an inner handler for that tag shadows an outer
handler (that is, tags always alias if identical indices); and whereas
before, `tagN` is not `tagM` and so we can order the tags arbitrarily
(that is, tags never alias if non-identical indices); now any two static
tag indices may or may not alias depending on the dynamic context of
each. Or, even in the same context, two may alias, because we leave the
match-predicate as an unspecified (user-chosen) algorithm during
unwinding. (This mirrors the reality that, for example, a Wasm instance
may import two tags, and dynamically these tags may be equal or
different at runtime, even instantiation-to-instantiation.) Cranelift's
only job is to faithfully carry the list of contexts and tags through to
the compiled-code metadata; and to ensure that they remain in the order
they were specified in the CLIF.

This PR introduces the Cranelift-level feature, and it will be used in
a subsequent PR that introduces Wasm exception handling. Because of
that, I've opted not to update the clif-utils runtest "runtime" to read
out contexts and do something with them -- we will have plenty of test
coverage via a bunch of Wasm tests for corner cases such as the above.
This PR does include filetests that show that contexts are carried
through to spillslots and those appear in the metadata.

Fixes #11285.

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Cranelift: introduce a function inliner (#11210)

* Cranelift: introduce a function inliner

This comit adds "inlining as a library" to Cranelift; it does _not_ provide a
complete, off-the-shelf inli

Cranelift: introduce a function inliner (#11210)

* Cranelift: introduce a function inliner

This comit adds "inlining as a library" to Cranelift; it does _not_ provide a
complete, off-the-shelf inlining solution. Cranelift's compilation context is
per-function and does not encompass the full call graph. It does not know which
functions are hot and which are cold, which have been marked the equivalent of
`#[inline(always)]` versus `#[inline(never)]`, etc... Only the Cranelift user
can understand these aspects of the full compilation pipeline, and these things
can be very different between (say) Wasmtime and `cg_clif`. Therefore, this
infrastructure does not attempt to define hueristics for when inlining a
particular call is likely beneficial. This module only provides hooks for the
Cranelift user to tell Cranelift whether a given call should be inlined or not,
and the mechanics to inline a callee into a particular call site when the user
directs Cranelift to do so.

This commit also creates a new kind of filetest that will always inline calls to
functions that have already been defined in the file. This lets us exercise the
inliner in filetests.

Fixes https://github.com/bytecodealliance/wasmtime/issues/4127

* Address review feedback

* Require callee bodies are pre-legalized

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Update Wasmtime to the 2024 Rust Edition (#10806)

* Update Wasmtime to the 2024 Rust Edition

Now that our MSRV supports the 2024 edition it's possible to make this
switch. This commit moves Wasmtim

Update Wasmtime to the 2024 Rust Edition (#10806)

* Update Wasmtime to the 2024 Rust Edition

Now that our MSRV supports the 2024 edition it's possible to make this
switch. This commit moves Wasmtime to the 2024 Edition to keep
up-to-date with Rust idioms and access many of the edition features
exclusive to the 2024 edition.

prtest:full

* Reformat with the 2024 edition

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Some fixes for try_call (#10593)

* Fix cranelift-frontend handling of try_call

* Implement eliminate_unreachable_code for exception tables

* Ensure try_call is considered a memory fence

* Don't e

Some fixes for try_call (#10593)

* Fix cranelift-frontend handling of try_call

* Implement eliminate_unreachable_code for exception tables

* Ensure try_call is considered a memory fence

* Don't error on try_call in the verifier if no TargetIsa is passed

* Don't clobber all registers for try_call unless the tail call conv is used

This way other consumers of Cranelift don't have to pay the cost of the
way Wasmtime will implement unwinding on exceptions.

* Allow SystemV call conv with try_call

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Cranelift: initial try_call / try_call_indirect (exception) support. (#10510)

* Cranelift: initial try_call / try_call_indirect (exception) support.

This PR adds `try_call` and `try_call_indirect`

Cranelift: initial try_call / try_call_indirect (exception) support. (#10510)

* Cranelift: initial try_call / try_call_indirect (exception) support.

This PR adds `try_call` and `try_call_indirect` instructions, and
lowerings on four of five ISAs (x86-64, aarch64, riscv64, pulley; s390x
has its own non-shared ABI code that will need separate work).

It extends CLIF to support these instructions as new kinds of branches,
and extends block-calls to accept `retN` and `exnN` block-call args that
carry the normal return values or exception payloads (respectively) into
the appropriate successor blocks.

It wires up the "normal return path" so that it continues to work.
It updates the ABI so that unwinding is possible without an initial
register state at throw: specifically, as per our RFC, all registers are
clobbered. It also includes metadata in the `MachBuffer` that describes
exception-catch destinations. However, no unwinder exists to interpret
these catch-destinations yet, so they are untested.

* Add try_call_indirect lowering as well.

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