Added Release Notes and moved comments and minor nits.

Author: Mr-Anyone

clang/docs/ReleaseNotes.rst

@@ -589,6 +589,7 @@ Bug Fixes in This Version
 - Fixed a crash with an invalid member function parameter list with a default
   argument which contains a pragma. (#GH113722)
 - Fixed assertion failures when generating name lookup table in modules. (#GH61065, #GH134739)
+- Fixed an assertion failure in constant compound literal statements. (#GH139160)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

clang/lib/Sema/SemaExpr.cpp

@@ -7241,16 +7241,16 @@ Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo,
           ? VK_PRValue
           : VK_LValue;
 
+  // C99 6.5.2.5
+  //  "If the compound literal occurs outside the body of a function, the
+  //  initializer list shall consist of constant expressions."
   if (IsFileScope)
     if (auto ILE = dyn_cast<InitListExpr>(LiteralExpr))
       for (unsigned i = 0, j = ILE->getNumInits(); i != j; i++) {
         Expr *Init = ILE->getInit(i);
-        // C99 6.5.2.5
-        //  "If the compound literal occurs outside the body of a function, the
-        //  initializer list shall consist of constant expressions."
         if (!Init->isTypeDependent() && !Init->isValueDependent() &&
             !Init->getType()->isDependentType())
-          if (!Init->isConstantInitializer(Context, false)) {
+          if (!Init->isConstantInitializer(Context, /*IsForRef=*/false)) {
             Diag(Init->getExprLoc(), diag::err_init_element_not_constant)
                 << Init->getSourceBitField();
             return ExprError();