Bulk port 64-bit x86 builtins to TableGen (#121043)
This PR follows https://github.com/llvm/llvm-project/pull/120831 for
x86-64.
Similar to that PR, this does a very mechanical port of X86 builtins to
TableGen. There is a *lot* of improvement available here to use TableGen
more effectively and collapse repeated structures. But those can now be
follow-up PRs that restructure *within* the `.td` file.
The current structure produces a file that exactly matches the original
X-macros except for the differences outlined in
https://github.com/llvm/llvm-project/pull/120831:
- Horizontal whitespace
- `long long` types now use `long long` outside of OpenCL, but switch to
`long` in OpenCL where relevant.
Otherwise, only the order of builtins change, and no tests regress.
