[Calyx] Verified-valid IR crashes in canonicalizer about circt HOT 1 OPEN

I've made some progress on this issue, and the reason for the crash is that the calyx.seq in the if structure is empty, and the pattern checking mechanism isn't strict enough, causing the crash when fetching the last op in the seq. After fixing this issue, a new problem arose.Apparently calyx.control is empty after canonicalize, which is the exact reason.

test.mlir:2:3: note: see current operation: 
"calyx.component"() ({
^bb0(%arg0: i1, %arg1: i1, %arg2: i1, %arg3: i1):
  %0:6 = "calyx.register"() {sym_name = "r"} : () -> (i1, i1, i1, i1, i1, i1)
  "calyx.wires"() ({
  ^bb0:
  }) : () -> ()
  "calyx.control"() ({
  ^bb0:
  }) : () -> ()
}) {function_type = (i1, i1, i1, i1) -> (), portAttributes = [{go}, {clk}, {reset}, {done}], portDirections = -8 : i4, portNames = ["go", "clk", "reset", "done"], sym_name = "main"} : () -> ()

I think the contents of calyx.control need to be scrutinized more closely, if there is no execute semantics in it, an error should be reported, it is too late to report an error after canonicalize.

from circt.