[lldb/DWARF] Fix PC value for artificial tail call frames for the "GNU" case

Summary:
The way that the support for the GNU dialect of tail call frames was
implemented in D80519 meant that the were r

[lldb/DWARF] Fix PC value for artificial tail call frames for the "GNU" case

Summary:
The way that the support for the GNU dialect of tail call frames was
implemented in D80519 meant that the were reporting very bogus PC values
which pointed into the middle of an instruction: the -1 trick is
necessary for the address to resolve to the right function, but we
should still be reporting a more realistic PC value -- I say "realistic"
and not "real", because it's very debatable what should be the correct
PC value for frames like this.

This patch achieves that my moving the -1 from SymbolFileDWARF into the
stack frame computation code. The idea is that SymbolFileDWARF will
merely report whether it has provided an address of the instruction
after the tail call, or the address of the call instruction itself. The
StackFrameList machinery uses this information to set the "behaves like
frame zero" property of the artificial frames (the main thing this flag
does is it controls the -1 subtraction when looking up the function
address).

This required a moderate refactor of the CallEdge class, because it was
implicitly assuming that edges pointing after the call were real calls
and those pointing the the call insn were tail calls. The class now
carries this information explicitly -- it carries three mostly
independent pieces of information:
- an address of interest in the caller
- a bit saying whether this address points to the call insn or after it
- whether this is a tail call

Reviewers: vsk, dblaikie

Subscribers: aprantl, mgrang, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D81010

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[lldb/DWARF] Add support for pre-standard GNU call site attributes

Summary:
The code changes are very straight-forward -- just handle both DW_AT_GNU
and DW_AT_call versions of all tags and attribute

[lldb/DWARF] Add support for pre-standard GNU call site attributes

Summary:
The code changes are very straight-forward -- just handle both DW_AT_GNU
and DW_AT_call versions of all tags and attributes. There is just one
small gotcha: in the GNU version, DW_AT_low_pc was used both for the
"return pc" and the "call pc" values, depending on whether the tag was
describing a tail call, while the official scheme uses different
attributes for the two things.

Reviewers: vsk, dblaikie

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D80519

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[lldb/DWARF] Reland: Use DW_AT_call_pc to determine artificial frame address

Reland with changes: the test modified in this change originally failed
on a Debian/x86_64 builder, and I suspect the cau

[lldb/DWARF] Reland: Use DW_AT_call_pc to determine artificial frame address

Reland with changes: the test modified in this change originally failed
on a Debian/x86_64 builder, and I suspect the cause was that lldb looked
up the line location for an artificial frame by subtracting 1 from the
frame's address. For artificial frames, the subtraction must not happen
because the address is already exact.

---

lldb currently guesses the address to use when creating an artificial
frame (i.e., a frame constructed by determining the sequence of (tail)
calls which must have happened).

Guessing the address creates problems -- use the actual address provided
by the DW_AT_call_pc attribute instead.

Depends on D76336.

rdar://60307600

Differential Revision: https://reviews.llvm.org/D76337

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Revert "[lldb/DWARF] Use DW_AT_call_pc to determine artificial frame address"

This reverts commit 6905394d153960ded3a7b884a9747ed2d4a6e8d8. The
changed test is failing on Debian/x86_64, possibly bec

Revert "[lldb/DWARF] Use DW_AT_call_pc to determine artificial frame address"

This reverts commit 6905394d153960ded3a7b884a9747ed2d4a6e8d8. The
changed test is failing on Debian/x86_64, possibly because lldb is
subtracting an offset from the DW_AT_call_pc address used for the
artificial frame:

http://lab.llvm.org:8011/builders/lldb-x86_64-debian/builds/7171/steps/test/logs/stdio

/home/worker/lldb-x86_64-debian/lldb-x86_64-debian/llvm-project/lldb/test/API/functionalities/tail_call_frames/unambiguous_sequence/main.cpp:6:17: error: CHECK-NEXT: expected string not found in input
// CHECK-NEXT: frame #1: 0x{{[0-9a-f]+}} a.out`func3() at main.cpp:14:3 [opt] [artificial]
^
<stdin>:3:2: note: scanning from here
frame #1: 0x0000000000401127 a.out`func3() at main.cpp:13:4 [opt] [artificial]

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[lldb/DWARF] Use DW_AT_call_pc to determine artificial frame address

lldb currently guesses the address to use when creating an artificial
frame (i.e., a frame constructed by determining the sequenc

[lldb/DWARF] Use DW_AT_call_pc to determine artificial frame address

lldb currently guesses the address to use when creating an artificial
frame (i.e., a frame constructed by determining the sequence of (tail)
calls which must have happened).

Guessing the address creates problems -- use the actual address provided
by the DW_AT_call_pc attribute instead.

Depends on D76336.

rdar://60307600

Differential Revision: https://reviews.llvm.org/D76337

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[lldb] Remove license headers from all test source files

Summary:
Around a third of our test sources have LLVM license headers. This patch removes those headers from all test
sources and also fixes

[lldb] Remove license headers from all test source files

Summary:
Around a third of our test sources have LLVM license headers. This patch removes those headers from all test
sources and also fixes any tests that depended on the length of the license header.

The reasons for this are:

* A few tests verify line numbers and will start failing if the number of lines in the LLVM license header changes. Once I landed my patch for valid SourceLocations in debug info we will probably have even more tests that verify line numbers.
* No other LLVM project is putting license headers in its test files to my knowledge.
* They make the test sources much more verbose than they have to be. Several tests have longer license headers than the actual test source.

For the record, the following tests had their line numbers changed to pass with the removal of the license header:
lldb-api :: functionalities/breakpoint/breakpoint_by_line_and_column/TestBreakpointByLineAndColumn.py
lldb-shell :: Reproducer/TestGDBRemoteRepro.test
lldb-shell :: Reproducer/TestMultipleTargets.test
lldb-shell :: Reproducer/TestReuseDirectory.test
lldb-shell :: ExecControl/StopHook/stop-hook-threads.test
lldb-shell :: ExecControl/StopHook/stop-hook.test
lldb-api :: lang/objc/exceptions/TestObjCExceptions.py

Reviewers: #lldb, espindola, JDevlieghere

Reviewed By: #lldb, JDevlieghere

Subscribers: emaste, aprantl, arphaman, JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D74839

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[lldb][test] Remove symlink for API tests.

Summary: Moves lldbsuite tests to lldb/test/API.

This is a largely mechanical change, moved with the following steps:

```
rm lldb/test/API/testcases
mkdi

[lldb][test] Remove symlink for API tests.

Summary: Moves lldbsuite tests to lldb/test/API.

This is a largely mechanical change, moved with the following steps:

```
rm lldb/test/API/testcases
mkdir -p lldb/test/API/{test_runner/test,tools/lldb-{server,vscode}}
mv lldb/packages/Python/lldbsuite/test/test_runner/test lldb/test/API/test_runner
for d in $(find lldb/packages/Python/lldbsuite/test/* -maxdepth 0 -type d | egrep -v "make|plugins|test_runner|tools"); do mv $d lldb/test/API; done
for d in $(find lldb/packages/Python/lldbsuite/test/tools/lldb-vscode -maxdepth 1 -mindepth 1 | grep -v ".py"); do mv $d lldb/test/API/tools/lldb-vscode; done
for d in $(find lldb/packages/Python/lldbsuite/test/tools/lldb-server -maxdepth 1 -mindepth 1 | egrep -v "gdbremote_testcase.py|lldbgdbserverutils.py|socket_packet_pump.py"); do mv $d lldb/test/API/tools/lldb-server; done
```

lldb/packages/Python/lldbsuite/__init__.py and lldb/test/API/lit.cfg.py were also updated with the new directory structure.

Reviewers: labath, JDevlieghere

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71151

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