[clang] nonblocking/nonallocating attributes: 2nd pass caller/callee analysis (PR #99656)

[Doug Wyatt via cfe-commits]

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@@ -8413,6 +8418,15 @@ void ASTReader::InitializeSema(Sema &S) {
         NewOverrides.applyOverrides(SemaObj->getLangOpts());
   }
 
+  for (GlobalDeclID ID : DeclsWithEffectsToVerify) {
+    Decl *D = GetDecl(ID);
+    if (auto *FD = dyn_cast<FunctionDecl>(D))
+      SemaObj->addDeclWithEffects(FD, FD->getFunctionEffects());
+    else if (auto *BD = dyn_cast<BlockDecl>(D))
+      SemaObj->addDeclWithEffects(BD, BD->getFunctionEffects());
+  }
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dougsonos wrote:

I'll make it `llvm_unreachable` (according to its docs:
```
/// Use this instead of assert(0). It conveys intent more clearly, suppresses
/// diagnostics for unreachable code paths, and allows compilers to omit
/// unnecessary code.
```

https://github.com/llvm/llvm-project/pull/99656