This extends https://github.com/llvm/llvm-project/pull/138577 to more UBSan checks, by changing SanitizerDebugLocation (formerly SanitizerScope) to add annotations if enabled for the specified ordinals.

Annotations will use the ordinal name if there is exactly one ordinal specified in the SanitizerDebugLocation; otherwise, it will use the handler name.

Updates the tests from https://github.com/llvm/llvm-project/pull/141814.

---------

Co-authored-by: Vitaly Buka <vitalybuka@google.com>

This patch is part of a stack that teaches Clang to generate Key Instructions
metadata for C and C++.

RFC:
https://discourse.llvm.org/t/rfc-improving-is-stmt-placement-for-better-interactive-debugging/82668

The feature is only functional in LLVM if LLVM is built with CMake flag
LLVM_EXPERIMENTAL_KEY_INSTRUCTIONs. Eventually that flag will be removed.

This connects the -fsanitize-annotate-debug-info plumbing (https://github.com/llvm/llvm-project/pull/138577) to CFI check codegen, using SanitizerAnnotateDebugInfo() (https://github.com/llvm/llvm-project/pull/139965) and SanitizerInfoFromCFIKind (https://github.com/llvm/llvm-project/pull/140117).

Note: SanitizerAnnotateDebugInfo() is updated to a public function because it is needed in ItaniumCXXABI.

Updates the tests from https://github.com/llvm/llvm-project/pull/139149.

This refactors existing code into a 'SanitizerInfoFromCFICheckKind'
helper function. This will be useful in future work to annotate CFI
checks with debug info
(https://github.com/llvm/llvm-project/pull/139809).

When initializing a global array, a loop is generated, but no
convergence is emitted for the loop. This fixes that up.

It isn't used and is redundant with the result pointer type argument.
A more reasonable API would only have LangAS parameters, or IR parameters,
not both. Not all values have a meaningful value for this. I'm also
not sure why we have this at all, it's not overridden by any targets and
further simplification is possible.

-fno-sanitize-merge (introduced in
https://github.com/llvm/llvm-project/pull/120464) nearly works for CFI:
code that calls EmitCheck will already check the merge options. This
patch fixes one EmitTrapCheck call, which did not check the merge
options, and for two other EmitTrapChecks, adds two TODOs that explain
why it is difficult to fix them.

The qualifier allows programmer to directly control how pointers are
signed when they are stored in a particular variable.

The qualifier takes three arguments: the signing key, a flag specifying
whether address discrimination should be used, and a non-negative
integer that is used for additional discrimination.

```
typedef void (*my_callback)(const void*);
my_callback __ptrauth(ptrauth_key_process_dependent_code, 1, 0xe27a) callback;
```

Co-Authored-By: John McCall rjmccall@apple.com