The cgen code mixes virtual insn enums with insn enums, and there isn't
an obvious (to me) way to unravel this atm, so disable the warning.
sim/lm32/decode.c:45:5: error:
implicit conversion from enumeration type 'CGEN_INSN_VIRTUAL_TYPE'
to different enumeration type 'CGEN_INSN_TYPE' (aka 'enum cgen_insn_type')
[-Werror,-Wenum-conversion]
45 | { VIRTUAL_INSN_X_INVALID, LM32BF_INSN_X_INVALID, LM32BF_SFMT_EMPTY },
| ~ ^~~~~~~~~~~~~~~~~~~~~~
Bug: https://sourceware.org/PR29752
a729245526