Introduce the `cranelift-bitset` crate; use it for stack maps in both Cranelift and Wasmtime (#8826)

* Introduce the `cranelift-bitset` crate

The eventual goal is to deduplicate bitset types betwee

Introduce the `cranelift-bitset` crate; use it for stack maps in both Cranelift and Wasmtime (#8826)

* Introduce the `cranelift-bitset` crate

The eventual goal is to deduplicate bitset types between Cranelift and Wasmtime,
especially their use in stack maps.

* Use the `cranelift-bitset` crate inside both Cranelift and Wasmtime

Mostly for stack maps, also for a variety of other random things where
`cranelift_codegen::bitset::BitSet` was previously used.

* Fix stack maps unit test in cranelift-codegen

* Uncomment `no_std` declaration

* Fix `CompountBitSet::reserve` method

* Fix `CompoundBitSet::insert` method

* Keep track of the max in a `CompoundBitSet`

Makes a bunch of other stuff easier, and will be needed for replacing
`cranelift_entity::EntitySet`'s bitset with this thing anyways.

* Add missing parens

* Fix a bug around insert and reserve

* Implement `with_capacity` in terms of `new` and `reserve`

* Rename `reserve` to `ensure_capacity`

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