Build gmp with --enable-fat
Build gmp with --enable-fat

This configure option ensures that the GMP library built into
our GCC tools will work on a wide variety of x86 chips rather
than baking in assumptions about the instruction set features
available on the build machine.

BUG= http://code.google.com/p/nativeclient/issues/detail?id=3086
TEST= trybots

R=bradnelson@google.com

Review URL: https://codereview.chromium.org/11312049

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@10164 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client