[clang] [llvm] [DXIL] Remove incompatible metadata types when preparing DXIL. (PR #136386)

[Justin Bogner via cfe-commits]

================
@@ -0,0 +1,39 @@
+; RUN: opt -S --dxil-prepare %s | FileCheck %s
+
+; This test tests the whitelist inside of DxilPrepare.cpp.
+; It ensures that certain metadata nodes are removed that aren't
+; in the whitelist, and that certain nodes may remain that
+; are on the whitelist.
----------------
bogner wrote:

I think we prefer the term allowlist these days. Also this is a bit verbose, maybe just
```
; Test that only metadata nodes that are valid in DXIL are allowed through
```

https://github.com/llvm/llvm-project/pull/136386