[GlobalISel] Unable to translate callbr to asm goto label

[agostonrobert]

Reproducer: https://godbolt.org/z/9joYWTbW4

The following C code:

int foo(int count) {
  asm goto ("b %l[stop]" :::: stop);
  return count;
stop:
  return 0;
}

compiled for any global isel target (after adapting the jump instruction), produces the error:

fatal error: error in backend: unable to translate instruction: callbr (in function: foo)

Dumping the passes shows the input instruction:

  callbr void asm sideeffect "b ${0:l}", "!i"() #1
          to label %3 [label %2], !dbg !20, !srcloc !21

Works fine with SelectionDAG (or GCC).