More nonsense fixing "bugs" with left shifts of signed values.  Yes,
the C standard does say this is undefined (and right shifts of signed
values are implementation defined BTW) but in practice there is no
problem with current machines.  1's complement is a thing of the past.

cpu/
	* m32c.cpu (f-src32-rn-unprefixed-QI): Shift before inverting.
	(f-src32-rn-prefixed-QI, f-dst32-rn-unprefixed-QI): Likewise.
	(f-dst32-rn-prefixed-QI): Likewise.
	(f-dsp-32-s32): Mask before shifting left.
	(f-dsp-48-u32, f-dsp-48-s32): Likewise.
	(f-bitbase32-16-s11-unprefixed): Multiply signed field rather than
	shifting left.
	(f-bitbase32-24-s11-prefixed, f-bitbase32-24-s19-prefixed): Likewise.
	(h-gr-SI): Mask before shifting.
opcodes/
	* m32c-ibld.c: Regenerate.