Real.maxFinite bug

[Henry Cejtin]

I would pitch reify and just use the C functions finite(), isnan() and isinf().

I looked at the code being generated in the Real_isFinite() case with -O2 and
although the double is passed on the stack (in 64-bit format), the statement
	word1 = ((Word*)&d)[1];
is being ignored.  The C standard has various warnings as I recall about these
kinds of funny casts actually requiring no specific results, so this could
even be legal, or it might just be a C bug.