Revision 193063 brought in calls to fraiseexcept() into libquadmath,
which caused a build regression on Fedora 16 (BLAG 160k actually) x86_64
while building an i686-linux-gnu native toolchain.

The problem is that glibc has an extern inline definition of
fraiseexcept that is introduced by including fenv.h (it's in
bits/fenv.h), and this definition requires SSE support regardless of
target arch of word width, so it doesn't work for an i686 native that
doesn't assume SSE registers and instructions are available.

This bug is fixed in newer versions of glibc, but I figured it wouldn't
hurt to have a work-around in place for libquadmath to build, detecting
that the extern inline in the header is broken and introducing a wrapper
that bypasses the header so as to use the out-of-line definition in the
math library.

Is this ok to install?