[co19] Skip 'main' optional parameters tests on dart2js

Fixes dart-lang/co19#952

Change-Id: Ic350695354f2c0c585e15c599ec227bbe7875cb3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/167560
Commit-Queue: Alexander Thomas <[email protected]>
Reviewed-by: Sigmund Cherem <[email protected]>
Reviewed-by: Alexander Thomas <[email protected]>

Author: sgrekhov

tests/co19/co19-dart2js.status

@@ -17,6 +17,8 @@ Language/Expressions/Object_Identity/object_t02: SkipByDesign # https://github.c
 Language/Expressions/Shift/integer_t01: SkipByDesign # big integer cannot be represented in JavaScript
 Language/Expressions/Shift/integer_t02: SkipByDesign # big integer cannot be represented in JavaScript
 Language/Expressions/Spawning_an_Isolate/new_isolate_t01: SkipByDesign
+Language/Libraries_and_Scripts/Scripts/main_optional_parameters_t01: SkipByDesign # https://github.com/dart-lang/co19/issues/952
+Language/Libraries_and_Scripts/Scripts/main_optional_parameters_t03: SkipByDesign # https://github.com/dart-lang/co19/issues/952
 Language/Metadata/before*: Skip # dart:mirrors not supported https://github.com/dart-lang/co19/issues/523.
 Language/Reference/Operator_Precedence/precedence_15_unary_prefix_t08: SkipByDesign # binary '~' produces different results in JavaScript and Dart
 LibTest/core/DateTime/DateTime.fromMicrosecondsSinceEpoch_A01_t01: SkipByDesign # microseconds are not supported in JavaScript