Move web regression tests into langauge suite.

Change-Id: Id1b61a345be94965f2ca8da228d694a1e13d2f92
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/406381
Commit-Queue: Nate Biggs <[email protected]>
Reviewed-by: Nate Bosch <[email protected]>

Author: natebiggs

tests/web/wasm/regress_59981_test.dart renamed to tests/language/exception/nested_catch_rethrow_test.dart

@@ -70,6 +70,28 @@ Future<void> doThrow4() async {
   }
 }
 
+Future<void> doThrow5(int v) async {
+  await Future.delayed(Duration(milliseconds: 10));
+  throw StateError('error $v');
+}
+
+Stream<int> _readLoop() async* {
+  try {
+    while (true) {
+      yield 1;
+      await doThrow5(0);
+    }
+  } catch (e) {
+    throw StateError('converted');
+  } finally {
+    try {
+      await doThrow5(1);
+    } catch (e) {
+      Expect.isTrue('$e'.contains('error 1'));
+    }
+  }
+}
+
 void main() async {
   try {
     await doThrow1();
@@ -102,4 +124,10 @@ void main() async {
     Expect.equals(e, 'inner');
     Expect.isTrue('$s'.contains('exception2'));
   }
+
+  try {
+    await for (var _ in _readLoop()) {}
+  } catch (e) {
+    Expect.isTrue('$e'.contains('converted'));
+  }
 }