[PATCH] [OpenCL] Disallow casting between address spaces

[Richard Smith]

  LGTM


================
Comment at: test/SemaOpenCL/address-spaces.cl:15
@@ +14,3 @@
+
+void explicit_cast(global int* g, local int* l, constant int* c, private int* p)
+{
----------------
Maybe also test that casts to the same address space are accepted?


http://llvm-reviews.chandlerc.com/D2526