Build [sparc]: Workaround for compiler bug in ~ gcc 4.7.4.
Gcc 4.7.4 and others "optimize" away calls to memcpy(), and replace
them with direct (unaligned) memory accesses. This generated broken
code for eg %F on sparc and other architectures that don't allow
unaligned memory accesses.
Note that the patch mentioned in the above bug report is in gcc 4.7.4,
but isn't sufficient.
We work around the issue by forcing the float extractor functions
to not be inlined on such architectures.