Add llvm-cas and llvm-cas-dump to toolchain

(cherry picked from commit ce25e25)

Author: rastogishubham

clang/cmake/caches/Apple-stage2.cmake

@@ -54,6 +54,8 @@ set(LLVM_TOOLCHAIN_TOOLS
   llvm-size
   llvm-cxxfilt
   llvm-config
+  llvm-cas
+  llvm-cas-dump
   CACHE STRING "")
 
 set(LLVM_BUILD_UTILS ON CACHE BOOL "")