Reapply "[Clang][Sema] placement new initializes typedef array with correct size

fixing the regression test failure

Author: mahtohappy

clang/docs/ReleaseNotes.rst

@@ -364,6 +364,8 @@ Improvements to Clang's diagnostics
 - Clang now uses the correct type-parameter-key (``class`` or ``typename``) when printing
   template template parameter declarations.
 
+- Clang now diagnoses requires expressions with explicit object parameters.
+
 Improvements to Clang's time-trace
 ----------------------------------
 
@@ -534,6 +536,8 @@ Bug Fixes to C++ Support
   Fixes (#GH70604), (#GH79754), (#GH84163), (#GH84425), (#GH86054), (#GH86398), and (#GH86399).
 - Fix a crash when deducing ``auto`` from an invalid dereference (#GH88329).
 - Fix a crash in requires expression with templated base class member function. Fixes (#GH84020).
+- Fix a crash caused by defined struct in a type alias template when the structure
+  has fields with dependent type. Fixes (#GH75221).
 - Fix placement new initializes typedef array with correct size. Fixes (#GH41441).
 
 Bug Fixes to AST Handling

clang/lib/Sema/TreeTransform.h

@@ -12867,7 +12867,7 @@ TreeTransform<Derived>::TransformCXXNewExpr(CXXNewExpr *E) {
   // Per C++0x [expr.new]p5, the type being constructed may be a
   // typedef of an array type.
   QualType AllocType = AllocTypeInfo->getType();
-  if (ArraySize) {
+  if (ArraySize && E->isTypeDependent()) {
     if (const ConstantArrayType *Array =
             SemaRef.Context.getAsConstantArrayType(AllocType)) {
       ArraySize = IntegerLiteral::Create(SemaRef.Context, Array->getSize(),