Disable -fwhole-program-vtables when compiling nacl_bootstrap_lib.
Disable -fwhole-program-vtables when compiling nacl_bootstrap_lib.

BUG=580389

Review URL: https://codereview.chromium.org/1868533003

sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client