Register counts are unsigned
Skip the top <arg-count> stack entries on call-reg-save
Factored out funcargs_ty_calc()
Fixes for variadic stack logic with float-saving
Working floating-point variadic functions

Needed:
	va_arg() offsetting changes
	stack reservation for __int128 types, aka xmm0-7
Fixed uninitialised vreg in special case movzlq code
Moved working float tests
Added -fintegral-float-load to control int->float loading

If a float can be represented in an int, we don't need to load it from
labelled memory, we can convert via an integral register. The -fno-
option of this flag disables this.
Removed dodgy frame-pointer stack reservation
Comment register spills
Stack snapshotting and temporary space reclaim

This fixes the issue where register juggling would spill registers onto
the stack after we've laid out our stack-passing arguments already.