Use int32 types instead of target_ulong when computing ICC. This
simplifies the generated code for 32-bit host and 64-bit guest.
Use the same simplified expressions for ICC as were already used
for XCC in carry flag generation.
Simplify the ADD carry generation to not consider a possible carry-in.
Use the more complex carry computation for ADDX only. Use the same
carry algorithm for the XCC result of ADDX. Similarly for SUB/SUBX.
Use the ADD carry generation functions for TADD/TADDTV. Similarly
for SUB and TSUB/TSUBTV.
Tidy the code with respect to CODING_STYLE.
Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>