0.9.7.8:

0.9.7.8:
	X86-64 floating point changes:

	* Create FP zeroes with XORPS/XORPD on instead of MOVQ XMM15.
        * Don't zero XMM15 after every foreign call (not needed anymore
          thanks to previous change)
        * Add SQRTSS/SQRTSD instructions
        * Use SQRTSD for implementing %SQRT, instead of calling to C
        * Replace &REST in SC-CASE lambda list with &BODY (for better
          Slime indentation)