[clang] [clang][Sema] Fix a bug when instantiating a lambda with requires clause (PR #65193)

[Erich Keane via cfe-commits]

================
@@ -2256,33 +2256,55 @@ ExprResult Sema::BuildBlockForLambdaConversion(SourceLocation CurrentLocation,
   return BuildBlock;
 }
 
+static FunctionDecl *getPatternFunctionDecl(FunctionDecl *FD) {
+  if (FD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization) {
+    while (FD->getInstantiatedFromMemberFunction())
+      FD = FD->getInstantiatedFromMemberFunction();
+    return FD;
+  }
+
+  if (FD->getTemplatedKind() == FunctionDecl::TK_DependentNonTemplate)
+    return FD->getInstantiatedFromDecl();
+
+  FunctionTemplateDecl *FTD = FD->getPrimaryTemplate();
+  if (!FTD)
+    return nullptr;
+
+  while (FTD->getInstantiatedFromMemberTemplate())
+    FTD = FTD->getInstantiatedFromMemberTemplate();
+
+  return FTD->getTemplatedDecl();
+}
+
 Sema::LambdaScopeForCallOperatorInstantiationRAII::
     LambdaScopeForCallOperatorInstantiationRAII(
-        Sema &SemasRef, FunctionDecl *FD, MultiLevelTemplateArgumentList MLTAL,
-        LocalInstantiationScope &Scope)
-    : FunctionScopeRAII(SemasRef) {
+        Sema &SemaRef, FunctionDecl *FD, MultiLevelTemplateArgumentList MLTAL,
+        LocalInstantiationScope &Scope, bool shouldAddDeclsFromParentScope)
----------------
erichkeane wrote:

```suggestion
        LocalInstantiationScope &Scope, bool ShouldAddDeclsFromParentScope)
```

https://github.com/llvm/llvm-project/pull/65193