Partial implementation of PR3342: break out pointer sign 
incompatibilities in assignments from other pointer incompatibilities.  
Based off of the patch in PR3342.  (This doesn't implement -Wno-pointer-sign,
but I don't know the driver code very well.)



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67494 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 64cc088..8bc5a60 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -2146,7 +2146,13 @@
     /// IncompatiblePointer - The assignment is between two pointers types that
     /// are not compatible, but we accept them as an extension.
     IncompatiblePointer,
-    
+
+    /// IncompatiblePointer - The assignment is between two pointers types which
+    /// point to integers which have a different sign, but are otherwise identical.
+    /// This is a subset of the above, but broken out because it's by far the most
+    /// common case of incompatible pointers.
+    IncompatiblePointerSign,
+
     /// CompatiblePointerDiscardsQualifiers - The assignment discards
     /// c/v/r qualifiers, which we accept as an extension.
     CompatiblePointerDiscardsQualifiers,