Initial support for MIPS16e in virtualmips emulator

Also:
- A few bugfixes in virtualmips
- Compile Smaller C (smlrc) using MIPS16e
  (this frees up ~20KB of space for smlrc improvements)
TBD:
- MIPS16e disassembler in virtualmips

src/cmd/smlrc/Makefile

@@ -33,3 +33,4 @@ clean:
 		rm -f *.o smlrc smlrc.dis smlrc.elf
 ###
 smlrc.o: smlrc.c cgmips.c
+		${CC} ${CFLAGS} -mips16 smlrc.c -c -o $@