[clang][Interp] Fix reporting invalid new/delete expressions

This should be a CCEDiag call and we do *not* abort because of it.

Author: tbaederr

clang/lib/AST/Interp/Interp.cpp

@@ -728,8 +728,8 @@ bool CheckDynamicMemoryAllocation(InterpState &S, CodePtr OpPC) {
     return true;
 
   const SourceInfo &E = S.Current->getSource(OpPC);
-  S.FFDiag(E, diag::note_constexpr_new);
-  return false;
+  S.CCEDiag(E, diag::note_constexpr_new);
+  return true;
 }
 
 bool CheckNewDeleteForms(InterpState &S, CodePtr OpPC, bool NewWasArray,

clang/test/AST/Interp/new-delete.cpp

@@ -560,4 +560,9 @@ constexpr int a() { // both-error {{never produces a constant expression}}
 }
 static_assert(a() == 1, ""); // both-error {{not an integral constant expression}} \
                              // both-note {{in call to 'a()'}}
+
+
+static_assert(true ? *new int : 4, ""); // both-error {{expression is not an integral constant expression}} \
+                                        // both-note {{read of uninitialized object is not allowed in a constant expression}}
+
 #endif