test/passes/merge-blocks_remove-unused-brs.txt

(module
 (type $i32_=>_none (func (param i32)))
 (func $func (param $x i32)
  (loop $loop
   (block $out
    (block
     (br_if $out
      (local.get $x)
     )
     (nop)
     (br $loop)
    )
   )
  )
 )
)