Merge pull request #6724 from EOSIO/fix_baked_macos_llvm_dir_16x

Set proper directory for baked in macOS LLVM_DIR - 1.6.x

CMakeLists.txt

@@ -17,7 +17,7 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/CMakeModules")
 if (UNIX)
    if (APPLE)
       if (LLVM_DIR STREQUAL "" OR NOT LLVM_DIR)
-         set(LLVM_DIR "/usr/local/Cellar/llvm@4/4.0.1/lib/cmake/llvm")
+         set(LLVM_DIR "/usr/local/opt/llvm@4/lib/cmake/llvm/")
       endif()
    endif()
 endif()