Bulk port 64-bit x86 builtins to TableGen

This PR follows #120831 (the PR contains both, only review the last
commit here as the other commit will be reviewed on the other PR).

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 #120831:

- Horizontal whitespace
- `long long` types now use `long long` outside of OpenCL, but switch to
  `long` in OpenCL (if relevant at all).

Otherwise, only the order of builtins change, and no tests regress.

Author: chandlerc

clang/include/clang/Basic/BuiltinsX86.td

@@ -10,22 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-include "clang/Basic/BuiltinsBase.td"
-
-class X86Builtin<string prototype> : TargetBuiltin {
-  let Spellings = ["__builtin_ia32_" # NAME];
-  let Prototype = prototype;
-}
-
-class X86NoPrefixBuiltin<string prototype> : TargetBuiltin {
-  let Spellings = [NAME];
-  let Prototype = prototype;
-}
-
-class X86LibBuiltin<string prototype> : TargetLibBuiltin {
-  let Spellings = [NAME];
-  let Prototype = prototype;
-}
+include "clang/Basic/BuiltinsX86Base.td"
 
 def rdpmc : X86Builtin<"unsigned long long int(int)">;
 def rdtsc : X86Builtin<"unsigned long long int()">;

clang/include/clang/Basic/BuiltinsX86Base.td

@@ -0,0 +1,28 @@
+//===--- BuiltinsX86Base.td - X86 Builtin function classes ------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the X86-specific builtin function classes.
+//
+//===----------------------------------------------------------------------===//
+
+include "clang/Basic/BuiltinsBase.td"
+
+class X86Builtin<string prototype> : TargetBuiltin {
+  let Spellings = ["__builtin_ia32_" # NAME];
+  let Prototype = prototype;
+}
+
+class X86NoPrefixBuiltin<string prototype> : TargetBuiltin {
+  let Spellings = [NAME];
+  let Prototype = prototype;
+}
+
+class X86LibBuiltin<string prototype> : TargetLibBuiltin {
+  let Spellings = [NAME];
+  let Prototype = prototype;
+}