[llvm] [DirectX] Use an allow-list of DXIL compatible module metadata (PR #165290)

[Deric C. via llvm-commits]

================
@@ -364,6 +364,16 @@ static void cleanModuleFlags(Module &M) {
     M.addModuleFlag(Flag.Behavior, Flag.Key->getString(), Flag.Val);
 }
 
+using GlobalMDList = std::array<StringLiteral, 7>;
+
+// The following are compatible with DXIL but not emit with clang, they can
+// be added when applicable:
+// dx.typeAnnotations, dx.viewIDState, dx.dxrPayloadAnnotations
+static GlobalMDList CompatibleNamedModuleMDs = {
+    "llvm.ident",     "llvm.module.flags", "dx.resources",   "dx.valver",
+    "dx.shaderModel", "dx.version",        "dx.entryPoints",
+};
----------------
Icohedron wrote:

This is a very nit-picky thing but I would put each element of the list on its own line.
One of the benefits is if there is a new commit, the diff will show the line(s) added or removed as opposed to a reviewer needing to scan for a change in a single line.

```suggestion
static GlobalMDList CompatibleNamedModuleMDs = {
    "llvm.ident",
    "llvm.module.flags",
    "dx.resources",
    "dx.valver",
    "dx.shaderModel",
    "dx.version",
    "dx.entryPoints",
};
```

https://github.com/llvm/llvm-project/pull/165290