remap cincoffsetimm to op-imm-32 and make cincoffset with rs2=x0 deco…

…de as cmove

unratified/rv64_cheri

@@ -1,12 +1,14 @@
 lc                 rd rs1          imm12   14..12=4 6..2=0x03 1..0=3
 sc                 imm12hi rs1 rs2 imm12lo 14..12=4 6..2=0x08 1..0=3
 
-#6-bit immediate fits, should hopefully be enough?
-cincoffsetimm     rd rs1 imm6 31..26=1     14..12=1 6..2=0x04 1..0=3
+#need to ADDIW
+cincoffsetimm     rd rs1 imm12            14..12=2 6..2=0x06 1..0=3
 #5-bit immediate and 25 says whether to shift it
-csetboundsimm     rd rs1 imm5 31..26=1     14..12=5 6..2=0x04 1..0=3
+csetboundsimm     rd rs1 imm5 31..26=1    14..12=5 6..2=0x04 1..0=3
 
-cincoffset        rd rs1 rs2      31..25=6 14..12=0 6..2=0x0C 1..0=3
+#if rs2=x0 decode as cmove
+cincoffset        rd rs1 rs2      31..25=6 14..12=0 6..2=0x06 1..0=3
+cmove             rd rs1 24..20=0 31..25=6 14..12=0 6..2=0x06 1..0=3
 csetaddr          rd rs1 rs2      31..25=6 14..12=1 6..2=0x0C 1..0=3
 candperm          rd rs1 rs2      31..25=6 14..12=2 6..2=0x0C 1..0=3
 csethigh          rd rs1 rs2      31..25=6 14..12=3 6..2=0x0C 1..0=3
@@ -19,7 +21,6 @@ csetboundsinexact rd rs1 rs2      31..25=7 14..12=1 6..2=0x0C 1..0=3
 
 cgettag           rd rs1 31..25=8 24..20=0 14..12=0 6..2=0x0C 1..0=3
 cgetperm          rd rs1 31..25=8 24..20=1 14..12=0 6..2=0x0C 1..0=3
-cmove             rd rs1 31..25=8 24..20=2 14..12=0 6..2=0x0C 1..0=3
 csetmode          rd rs1 31..25=8 24..20=3 14..12=0 6..2=0x0C 1..0=3
 cgethigh          rd rs1 31..25=8 24..20=4 14..12=0 6..2=0x0C 1..0=3
 cgetbase          rd rs1 31..25=8 24..20=5 14..12=0 6..2=0x0C 1..0=3