[dart2wasm] Fix runtime type tests

emitTypeTest optimizes a test like `x is List<T>` where `x :
Iterable<T>`, i.e. tested-against type is a subtype of the operand's
static type. In these cases we can check just the class ID of the
operand without checking the type arguments.

However this optimization cannot be done when the types don't have same
number of type arguments. Example:

    class H1<T> {}

    bool test(Object o) {
      return o is H1<num>;
    }

    void main() {
      print(test(H1<Object>()));
    }

Here `H1<num> <: Object`, but we still need to check the type parameter.

This CL checks that the types have the same number of type arguments
before optimizing the test.

Fixes #51187.

This fix reveals another bug in `static_interop_test`, which is tracked
in #51200. The test is updated to work around the bug for now.

New passing tests:

- co19/LanguageFeatures/Patterns/matching_cast_A01_t01
- co19/LanguageFeatures/Patterns/matching_list_A01_t01
- co19/LanguageFeatures/Patterns/matching_list_A01_t02
- co19/LanguageFeatures/Patterns/matching_object_A01_t01
- co19/LanguageFeatures/Patterns/matching_object_A01_t02
- co19/LanguageFeatures/Patterns/record_A01_t03
- co19/LanguageFeatures/Patterns/record_A01_t06
- co19/LanguageFeatures/Patterns/record_A01_t07
- co19/LanguageFeatures/Patterns/record_A01_t08
- co19/LanguageFeatures/Patterns/record_A01_t09
- language/generic/deep_test
- language/generic_methods/type_expression_test
- language/patterns/object_pattern_inference_test

Change-Id: Ibd9615666b7f7538c2a3f03fb7f5ebe9b16c3d54
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/292881
Reviewed-by: Joshua Litt <joshualitt@google.com>
Commit-Queue: Ömer Ağacan <omersa@google.com>

pkg/dart2wasm/lib/types.dart

@@ -611,16 +611,23 @@ class Types {
     }
 
     if (type.typeArguments.any((t) => t is! DynamicType)) {
-      // If the tested-against type as an instance of the static operand type
-      // has the same type arguments as the static operand type, it is not
-      // necessary to test the type arguments.
+      // Type has at least one type argument that is not `dynamic`.
+      //
+      // In cases like `x is List<T>` where `x : Iterable<T>` (tested-against
+      // type is a subtype of the operand's static type and the types have same
+      // number of type arguments), it is not necessary to test the type
+      // arguments.
       Class cls = translator.classForType(operandType);
       InterfaceType? base = translator.hierarchy
           .getTypeAsInstanceOf(type, cls,
               isNonNullableByDefault:
                   codeGen.member.enclosingLibrary.isNonNullableByDefault)
           ?.withDeclaredNullability(operandType.declaredNullability);
-      if (base != operandType) {
+
+      final sameNumTypeParams = operandType is InterfaceType &&
+          operandType.typeArguments.length == type.typeArguments.length;
+
+      if (!(sameNumTypeParams && base == operandType)) {
         makeType(codeGen, type);
         codeGen.call(translator.isSubtype.reference);
         _endPotentiallyNullableBlock();

tests/web/wasm/static_interop_test.dart

@@ -311,7 +311,7 @@ extension AnonymousJSClassExtension on AnonymousJSClass {
   external String? get bleep;
   external int? get goo;
   external int? get ooo;
-  external List<double>? saz;
+  external List<Object?>? saz;
   external List<double>? zoo;
 }