[mlir][arith] Add tests for i0 canonicalization (#89665)

Before #87193, the canonicalizer in arith crashed when attempting signed
extension on an i0 value. To hopefully avoid it happening again, this PR
introduces tests for canonicalization of arith operations with i0
values, focusing on operations related to bit width or signedness.

Author: Moxinilian

mlir/test/Dialect/Arith/canonicalize.mlir

@@ -2831,6 +2831,87 @@ func.func @unsignedExtendConstantResource() -> tensor<i16> {
   return %ext : tensor<i16>
 }
 
+// CHECK-LABEL: @extsi_i0
+//       CHECK:   %[[ZERO:.*]] = arith.constant 0 : i16
+//       CHECK:   return %[[ZERO]] : i16
+func.func @extsi_i0() -> i16 {
+  %c0 = arith.constant 0 : i0
+  %extsi = arith.extsi %c0 : i0 to i16
+  return %extsi : i16
+}
+
+// CHECK-LABEL: @extui_i0
+//       CHECK:   %[[ZERO:.*]] = arith.constant 0 : i16
+//       CHECK:   return %[[ZERO]] : i16
+func.func @extui_i0() -> i16 {
+  %c0 = arith.constant 0 : i0
+  %extui = arith.extui %c0 : i0 to i16
+  return %extui : i16
+}
+
+// CHECK-LABEL: @trunc_i0
+//       CHECK:   %[[ZERO:.*]] = arith.constant 0 : i0
+//       CHECK:   return %[[ZERO]] : i0
+func.func @trunc_i0() -> i0 {
+  %cFF = arith.constant 0xFF : i8
+  %trunc = arith.trunci %cFF : i8 to i0
+  return %trunc : i0
+}
+
+// CHECK-LABEL: @shli_i0
+//       CHECK:   %[[ZERO:.*]] = arith.constant 0 : i0
+//       CHECK:   return %[[ZERO]] : i0
+func.func @shli_i0() -> i0 {
+  %c0 = arith.constant 0 : i0
+  %shli = arith.shli %c0, %c0 : i0
+  return %shli : i0
+}
+
+// CHECK-LABEL: @shrsi_i0
+//       CHECK:   %[[ZERO:.*]] = arith.constant 0 : i0
+//       CHECK:   return %[[ZERO]] : i0
+func.func @shrsi_i0() -> i0 {
+  %c0 = arith.constant 0 : i0
+  %shrsi = arith.shrsi %c0, %c0 : i0
+  return %shrsi : i0
+}
+
+// CHECK-LABEL: @shrui_i0
+//       CHECK:   %[[ZERO:.*]] = arith.constant 0 : i0
+//       CHECK:   return %[[ZERO]] : i0
+func.func @shrui_i0() -> i0 {
+  %c0 = arith.constant 0 : i0
+  %shrui = arith.shrui %c0, %c0 : i0
+  return %shrui : i0
+}
+
+// CHECK-LABEL: @maxsi_i0
+//       CHECK:   %[[ZERO:.*]] = arith.constant 0 : i0
+//       CHECK:   return %[[ZERO]] : i0
+func.func @maxsi_i0() -> i0 {
+  %c0 = arith.constant 0 : i0
+  %maxsi = arith.maxsi %c0, %c0 : i0
+  return %maxsi : i0
+}
+
+// CHECK-LABEL: @minsi_i0
+//       CHECK:   %[[ZERO:.*]] = arith.constant 0 : i0
+//       CHECK:   return %[[ZERO]] : i0
+func.func @minsi_i0() -> i0 {
+  %c0 = arith.constant 0 : i0
+  %minsi = arith.minsi %c0, %c0 : i0
+  return %minsi : i0
+}
+
+// CHECK-LABEL: @mulsi_extended_i0
+//       CHECK:   %[[ZERO:.*]] = arith.constant 0 : i0
+//       CHECK:   return %[[ZERO]], %[[ZERO]] : i0
+func.func @mulsi_extended_i0() -> (i0, i0) {
+  %c0 = arith.constant 0 : i0
+  %mulsi_extended:2 = arith.mulsi_extended %c0, %c0 : i0
+  return %mulsi_extended#0, %mulsi_extended#1 : i0, i0
+}
+
 {-#
   dialect_resources: {
     builtin: {