Disable clang optimization that has segmentation fault.

When compiling for aosp_fugu-userdebug, clang aborted in pass:

  Running pass 'Function Pass Manager' on module 'system/core/libmincrypt/p256_ec.c'.
  Running pass 'X86 DAG->DAG Instruction Selection' on function '@felem_square'

BUG: 18790528
Change-Id: I416c07cae4c1a9743655bc45bd33c10a5cc9b41f
Merge "Disable clang optimization that has segmentation fault."