[dart2js] Print powerset value in typemask toString methods.

We may find it useful later to add a more verbose stringification that
writes out the properties expressed by the powerset. For now, just
printing the int value is sufficient to debug e.g. test failures, and
it's relatively straightforward to manually convert an int to a set of
properties by looking at the definitions of the powerset domains.

Change-Id: I2397ffd83a6e86830f67c7f1ef811e33c0b7ff3c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/405567
Reviewed-by: Nate Biggs <[email protected]>

Author: fishythefish

pkg/compiler/lib/src/inferrer/typemasks/container_type_mask.dart

@@ -121,6 +121,7 @@ class ContainerTypeMask extends AllocationTypeMask {
 
   @override
   String toString() {
-    return 'Container($forwardTo, element: $elementType, length: $length)';
+    return 'Container($forwardTo, element: $elementType, length: $length, '
+        'powerset: ${TypeMask.powersetToString(powerset)})';
   }
 }

pkg/compiler/lib/src/inferrer/typemasks/dictionary_type_mask.dart

@@ -143,7 +143,7 @@ class DictionaryTypeMask extends MapTypeMask {
 
   @override
   String toString() {
-    return 'Dictionary($forwardTo, key: $keyType, '
-        'value: $valueType, map: $_typeMap)';
+    return 'Dictionary($forwardTo, key: $keyType, value: $valueType, '
+        'map: $_typeMap, powerset: ${TypeMask.powersetToString(powerset)})';
   }
 }

pkg/compiler/lib/src/inferrer/typemasks/flat_type_mask.dart

@@ -879,6 +879,7 @@ class FlatTypeMask extends TypeMask {
       if (isExact) 'exact=${base!.name}',
       if (isSubclass) 'subclass=${base!.name}',
       if (isSubtype) 'subtype=${base!.name}',
+      'powerset=${TypeMask.powersetToString(powerset)}',
     ], '|');
     buffer.write(']');
     return buffer.toString();

pkg/compiler/lib/src/inferrer/typemasks/map_type_mask.dart

@@ -134,6 +134,7 @@ class MapTypeMask extends AllocationTypeMask {
 
   @override
   String toString() {
-    return 'Map($forwardTo, key: $keyType, value: $valueType)';
+    return 'Map($forwardTo, key: $keyType, value: $valueType, '
+        'powerset: ${TypeMask.powersetToString(powerset)})';
   }
 }

pkg/compiler/lib/src/inferrer/typemasks/record_type_mask.dart

@@ -445,7 +445,8 @@ class RecordTypeMask extends TypeMask {
 
   @override
   String toString() {
-    return '[Record($shape, $types)]';
+    return '[Record($shape, $types, '
+        'powerset: ${TypeMask.powersetToString(powerset)})]';
   }
 
   @override

pkg/compiler/lib/src/inferrer/typemasks/set_type_mask.dart

@@ -95,5 +95,7 @@ class SetTypeMask extends AllocationTypeMask {
   int get hashCode => Hashing.objectHash(elementType, super.hashCode);
 
   @override
-  String toString() => 'Set($forwardTo, element: $elementType)';
+  String toString() =>
+      'Set($forwardTo, element: $elementType, '
+      'powerset: ${TypeMask.powersetToString(powerset)})';
 }

pkg/compiler/lib/src/inferrer/typemasks/type_mask.dart

@@ -552,4 +552,6 @@ abstract class TypeMask implements AbstractValue {
     MemberHierarchyBuilder memberHierarchyBuilder,
     JClosedWorld closedWorld,
   );
+
+  static String powersetToString(Bitset powerset) => '$powerset';
 }

pkg/compiler/lib/src/inferrer/typemasks/union_type_mask.dart

@@ -488,7 +488,8 @@ class UnionTypeMask extends TypeMask {
       if (hasLateSentinel) 'sentinel',
       ...disjointMasks.map((TypeMask mask) => mask.toString()).toList()..sort(),
     ].join(", ");
-    return 'Union($masksString)';
+    return 'Union($masksString, '
+        'powerset: ${TypeMask.powersetToString(powerset)})';
   }
 
   @override

pkg/compiler/lib/src/inferrer/typemasks/value_type_mask.dart

@@ -70,6 +70,7 @@ class ValueTypeMask extends ForwardingTypeMask {
 
   @override
   String toString() {
-    return 'Value($forwardTo, value: ${value.toDartText(null)})';
+    return 'Value($forwardTo, value: ${value.toDartText(null)}, '
+        'powerset: ${TypeMask.powersetToString(powerset)})';
   }
 }