Run amdgpu-unify-metadata after build

Run this hack pass to cleanup the extra version metadata from the
linked bitcode files. Really these named nodes should have a setvector
behavior. We probably shouldn't run this in the backend, the main
reason we have it is from all the duplicates from the libraries. Saves
about 1K in total bitcode file size.

Change-Id: Ibc59fb57113b2734700d1717262c5aefa5c59c55

cmake/OCL.cmake

@@ -136,7 +136,7 @@ macro(opencl_bc_lib)
     # Extra link step with internalize
     COMMAND $<TARGET_FILE:llvm-link> -internalize -only-needed "${name}.link0${LIB_SUFFIX}"
       -o "${OUT_NAME}${LIB_SUFFIX}" ${internal_link_libs}
-    COMMAND $<TARGET_FILE:opt> -passes=strip
+    COMMAND $<TARGET_FILE:opt> -passes=amdgpu-unify-metadata,strip
       -o "${OUT_NAME}${STRIP_SUFFIX}" "${OUT_NAME}${LIB_SUFFIX}"
     COMMAND "${PREPARE_BUILTINS}"
       -o ${OUTPUT_BC_LIB} "${OUT_NAME}${STRIP_SUFFIX}"