[llvm] [DirectX] Infrastructure to collect shader flags for each function (PR #112967)

[Chris B via llvm-commits]

================
@@ -60,21 +62,54 @@ struct ComputedShaderFlags {
     return FeatureFlags;
   }
 
-  static ComputedShaderFlags computeFlags(Module &M);
+  uint64_t getModuleFlags() const {
+    uint64_t ModuleFlags = 0;
+#define DXIL_MODULE_FLAG(DxilModuleBit, FlagName, Str)                         \
+  ModuleFlags |= FlagName ? getMask(DxilModuleBit) : 0ull;
----------------
llvm-beanz wrote:

We have this exact expansion inside the `operator uint64_t` definition above. Should we maybe refactor this so that one uses the other instead of duplicating the expansion?

https://github.com/llvm/llvm-project/pull/112967