[CMake] Use add_llvm_tool_symlink's OUTPUT_DIR option
[CMake] Use add_llvm_tool_symlink's OUTPUT_DIR option

This is updating to take r288632 into account.

git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@288633 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb