[DirectX] Add target builtins (#134439)

- fixes #132303
- Moves dot2add from a language builtin to a target builtin.
-  Sets the scaffolding for Sema checks for DX builtins
-  Setup DirectX backend as able to have target builtins
- Adds a DX TargetBuiltins emitter in
`clang/lib/CodeGen/TargetBuiltins/DirectX.cpp`

GitOrigin-RevId: 16c84c4475b909d2de455a44139643c03fe3fe25
19 files changed
tree: e4f47b888284c7a6060aa35f59fea16067892fad
  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. AreaTeamMembers.txt
  17. CMakeLists.txt
  18. INSTALL.txt
  19. LICENSE.TXT
  20. Maintainers.rst
  21. NOTES.txt
  22. 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: