C.ADDI16SP, C.LWSP, C.JR, C.ADDIW, C.LDSP all have reserved
operands that were not diagnosed.
Backports commit 4cc16b3b9282e04fab8e84d136540757e82af019 from qemu
This eliminates all functions in insn_trans/trans_rvc.inc.c,
so the entire file can be removed.
Backports commit 0e68e240a9bd3b44a91cd6012f0e2bf2a43b9fe2 from qemu