Disable clang compilation for x86_64, mips, mips64.

Cannot boot up in emulator if libunwind is compiled with clang.
This change should allow clang compiled AOSP to boot up on x86_64,
but mips and mips64 still have other problems.

BUG: 25195800
Change-Id: Ifa8e1e9bdd7c15e08fe102875edc3ded38c0a048
1 file changed