[PATCH] Add handling for range metadata in ValueTracking isKnownNonZero

[hfinkel at anl.gov]

================
Comment at: lib/Analysis/ValueTracking.cpp:1534
@@ +1533,3 @@
+        ConstantRange Range(Lower->getValue(), Upper->getValue());
+        if( Range.contains(ZeroValue) )
+          return false;
----------------
space after if; no spaces after ( and before ).

================
Comment at: lib/Analysis/ValueTracking.cpp:1535
@@ +1534,3 @@
+        if( Range.contains(ZeroValue) )
+          return false;
+      }
----------------
Don't return here... there are other checks below that still might provide information.

http://reviews.llvm.org/D5947