Added checking for undefined results of '<<' and '>>' (shifting by too many bits, etc.)
This current implementation only works when both operands are concrete values; later we will add support for symbolic values.

llvm-svn: 47726
diff --git a/clang/Analysis/GRSimpleVals.cpp b/clang/Analysis/GRSimpleVals.cpp
index 4ed80af..8b5e3c8 100644
--- a/clang/Analysis/GRSimpleVals.cpp
+++ b/clang/Analysis/GRSimpleVals.cpp
@@ -82,6 +82,11 @@
               CheckerState->bad_divides_begin(),
               CheckerState->bad_divides_end(),
               "Division by zero/undefined value.");
+  
+  EmitWarning(Diag, SrcMgr,
+              CheckerState->undef_results_begin(),
+              CheckerState->undef_results_end(),
+              "Result of operation is undefined.");
       
 #ifndef NDEBUG
   if (Visualize) CheckerState->ViewGraph();