Pin clang for darwin to r487747c

Neither of versions in ToT (r522817, r530567, r536225) could compile
stable openjdk for x86 Mac platform. We'll wait for openjdk to adopt
to new compiler version,and then unpin.

Bug: 362507018
Change-Id: I0ad7125a98490460b256c8dbbfa458af9bc0963a
1 file changed