[Bug libitm/53113] Build fails in x86_avx.cc if AVX disabled by -mno-avx but supported by as

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53113

--- Comment #22 from H.J. Lu <hjl.tools at gmail dot com> ---
A patch is posted at

http://gcc.gnu.org/ml/gcc-patches/2013-12/msg01877.html