Revert "Revert r347417 "Re-Reinstate 347294 with a fix for the failures.""

It seems the two failing tests can be simply fixed after r348037

Fix 3 cases in Analysis/builtin-functions.cpp
Delete the bad CodeGen/builtin-constant-p.c for now

llvm-svn: 348053
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 88f7dce..dbceaa7 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -2523,9 +2523,9 @@
       Count = CAT->getSize().getZExtValue();
     else if (const auto *VAT = dyn_cast<VariableArrayType>(Ty)) {
       if (Expr *Size = VAT->getSizeExpr()) {
-        llvm::APSInt V;
-        if (Size->EvaluateAsInt(V, CGM.getContext()))
-          Count = V.getExtValue();
+        Expr::EvalResult Result;
+        if (Size->EvaluateAsInt(Result, CGM.getContext()))
+          Count = Result.Val.getInt().getExtValue();
       }
     }