NV fp parser: Add support for condition codes

NV fp parser: Add support for condition codes

Conditional write masks and the condition-code based KIL instruction
are all supported.  The specific behavior of KIL in the following
shader may or may not match the behavior of other implementations:

!!ARBfp1.0
	TEMP	GT;
	MOVC	GT, fragment.texcoord[0];
	KIL	GT.x;
	END

Should be it interpreted as 'KIL srcReg' or as 'KIL ccTest'?  The
current parser will interpret it as 'KIL srcReg'.