[clang] [llvm] Add support for Windows hot-patching (PR #138972)

[Alexandre Ganea via cfe-commits]

================
@@ -0,0 +1,20 @@
+// This verifies that hotpatch function attributes are correctly propagated when compiling directly to OBJ.
+//
+// RUN: %clang_cl -c --target=x86_64-windows-msvc -O2 /Z7 -fms-hotpatch-functions-file=%S/ms-hotpatch-functions.txt /Fo%t.obj %s
----------------
aganea wrote:

It is simply to be clear about what is supported or not, if someone inadvertently tries to use these options on unsupported archs.

https://github.com/llvm/llvm-project/pull/138972