* v850-opc.c (extract_v8): Rearrange to make it obvious this

	is the inverse of corresponding insert function.
	(extract_d22, extract_u9, extract_r4): Likewise.
	(extract_d9): Correct sign extension.
	(extract_d16_15): Don't assume "long" is 32 bits, and don't
	rely on implementation defined behaviour for shift right of
	signed types.
	(extract_d16_16, extract_d17_16, extract_i9): Likewise.
	(extract_d23): Likewise, and correct mask.