target/sparc: Split psr and xcc into components

target/sparc: Split psr and xcc into components

Step in removing CC_OP: change the representation of CC_OP_FLAGS.
The 8 bits are distributed between 6 variables, which should make
it easy to keep up to date.

The code within cc_helper.c is quite ugly but is only temporary.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Acked-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>