Unable to break out of the loop in SPIR-V

[kvark]

Description
Getting invalid SPIR-V out of Naga:

error: line 36: Block '23[%23]' branches to the loop continue target '16[%16]', but is not contained in the associated loop construct '13[%13]'
OpBranch %16

Repro steps
Program:

fn main() {
    for (var i = 0; i < 4; i += 1) {
      break;
    }
}

Expected vs observed behavior
Expected to produce valid SPIR-V