[SPIRV] Add Target Builtins using Distance ext as an example (#121598)

- Update pr labeler so new SPIRV files get properly labeled.
- Add distance target builtin to BuiltinsSPIRV.td.
- Update TargetBuiltins.h to account for spirv builtins.
- Update clang basic CMakeLists.txt to build spirv builtin tablegen.
- Hook up sema for SPIRV in Sema.h|cpp, SemaSPIRV.h|cpp, and
SemaChecking.cpp.
- Hookup sprv target builtins to SPIR.h|SPIR.cpp target.
- Update GBuiltin.cpp to emit spirv intrinsics when we get the expected
spirv target builtin.

Consensus was reach in this RFC to add both target builtins and pattern
matching:
https://discourse.llvm.org/t/rfc-add-targetbuiltins-for-spirv-to-support-hlsl/83329.

pattern matching will come in a separate pr this one just sets up the
groundwork to do target builtins for spirv.

partially resolves
[#99107](https://github.com/llvm/llvm-project/issues/99107)

GitOrigin-RevId: 21edac25f09faee23015c6a69d95fcbda287efe2
15 files changed
tree: ca4e97073247f72e42b835c29347dbb6c047a839
  1. bindings/
  2. cmake/
  3. docs/
  4. examples/
  5. include/
  6. lib/
  7. runtime/
  8. test/
  9. tools/
  10. unittests/
  11. utils/
  12. www/
  13. .clang-format
  14. .clang-tidy
  15. .gitignore
  16. CMakeLists.txt
  17. INSTALL.txt
  18. LICENSE.TXT
  19. Maintainers.rst
  20. NOTES.txt
  21. README.md
README.md

C language Family Front-end

Welcome to Clang.

This is a compiler front-end for the C family of languages (C, C++ and Objective-C) which is built as part of the LLVM compiler infrastructure project.

Unlike many other compiler frontends, Clang is useful for a number of things beyond just compiling code: we intend for Clang to be host to a number of different source-level tools. One example of this is the Clang Static Analyzer.

If you're interested in more (including how to build Clang) it is best to read the relevant websites. Here are some pointers: