This eliminates all functions in insn_trans/trans_rvc.inc.c,
so the entire file can be removed.
Backports commit 0e68e240a9bd3b44a91cd6012f0e2bf2a43b9fe2 from qemu
This eliminates about half of the complicated decode
bits within insn_trans/trans_rvc.inc.c.
Backports commit c2cfb97c01a3636867c1a4a24f8a99fd8c6bed28 from qemu
Special handling for IMM==0 is the only difference between
RVC shifti and RVI shifti. This can be handled with !function.
Backports commit 6cafec92f1c862a9754ef6a28be68ba7178a284d from qemu
In some cases this allows us to directly use the insn32
translator function. In some cases we still need a shim.
Backports commit e1d455dd91c935c714412dafeb24db947429a929 from qemu