[PATCH] Add a truncation warning for values under a bitwise or

[Dmitri Gribenko]

================
Comment at: lib/Sema/SemaChecking.cpp:4782
@@ +4781,3 @@
+static bool IsBitwiseOrWithConstant(Sema &S, llvm::APSInt &Value, Expr *E) {
+  E = E->IgnoreImpCasts();
+  if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
----------------
IgnoreParenImpCasts?  Does `x = (y | 0xfff);`work?  Please add this test anyway.


http://llvm-reviews.chandlerc.com/D405