Fix for PR3433: map __alignof__ to preferred alignment.  (This was 
partially done in r65258.)

llvm-svn: 65260
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index e3c4809..103bc37 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -960,7 +960,7 @@
 
   // Get information about the alignment.
   unsigned CharSize = Info.Ctx.Target.getCharWidth();
-  return Info.Ctx.getTypeAlign(Ty) / CharSize;
+  return Info.Ctx.getPreferredTypeAlign(Ty) / CharSize;
 }
 
 unsigned IntExprEvaluator::GetAlignOfExpr(const Expr *E) {