Add e500 version of fetestexceptflag.

When I added fetestexceptflag, I missed that e500 was another case
that needed its own version because saved exceptions were not directly
stored in a form that could be ANDed with exception bits (they were
stored with exceptions in SPE form, but the FE_* macros always use the
classic hard-float form).  This patch adds an e500 version with the
required call to __fexcepts_from_spe to convert from one form to the
other.

Tested for e500.

	* sysdeps/powerpc/powerpc32/e500/nofpu/fetestexceptflag.c: New
	file.