build: compile translate.o with -fno-gcse option on GCC 4.6.x and 4.7.[012]

build: compile translate.o with -fno-gcse option on GCC 4.6.x and 4.7.[012]

These versions of GCC require insane (>2GB) amounts of memory to compile
translate.o.  As a countermeasure, disable the culprit optimization pass.
This should fix the buildbot failure for default_x86_64_fedora16.  Anyway
this is a good thing to do because people will try to compile 1.3 with
less than 2GB of memory and complain.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>