[dart2wasm] Use native int parsing in JSCM

JSCM (JS compatibility mode) started as an experiment to have a
compilation mode that is semantically as close to dart2js as possible,
to make migration from dart2js easy.

However we've since decided to follow VM semantics in dart2wasm, and
JSCM now mainly exists to test JS-backed typed data and string classes.

The default mode allocates Wasm-array-backed strings and typed data
classes when they are allocated in Dart, so the JS-backed classes are
are only tested in JS interop tests in the default mode. In JSCM we only
have JS-backed classes so all tests allocate JS-backed typed data and
string classes.

Integer parsing in JSCM is currently just a `parseInt` JS call, which is
not compatible with the VM or dart2js semantics.

Since which one to follow does not make any difference in terms of test
coverage of dart2wasm standard library, do the simple thing and reuse
the default mode's `int` parser.

Fixes these tests in JSCM:

- co19/LanguageFeatures/Digit-separators/parse_A01_t01
- co19/LanguageFeatures/Digit-separators/parse_A01_t02
- co19/LanguageFeatures/Digit-separators/parse_A01_t03
- co19/LanguageFeatures/Digit-separators/parse_A03_t01
- co19/LanguageFeatures/Digit-separators/parse_A03_t02
- co19/LanguageFeatures/Digit-separators/parse_A03_t03
- co19/LibTest/core/Uri/parseIPv6Address_A02_t01
- co19/LibTest/core/int/parse_A01_t02
- co19/LibTest/core/int/parse_A02_t01
- co19/LibTest/core/int/parse_A03_t02
- co19/LibTest/core/int/parse_A04_t02
- corelib/int_parse_radix_int64_test/02
- corelib/int_parse_radix_test/02
- corelib/int_parse_radix_test/none
- corelib/int_parse_with_limited_ints_test
- corelib/int_try_parse_test
- corelib/integer_parsed_arith_vm_test
- corelib/integer_parsed_div_rem_vm_test/01
- corelib/integer_parsed_div_rem_vm_test/none
- corelib/integer_parsed_mul_div_vm_test
- corelib/num_parse_test/01
- corelib/num_parse_test/none
- corelib/num_try_parse_test
- corelib/uri_ipv4_test
- corelib/uri_test
- language/operator/arithmetic_int64_test
- language/operator/arithmetic_test
- lib/async/stream_controller_test
- lib/convert/json_chunk_test
- lib/convert/json_test
- lib/convert/json_utf8_chunk_test
- lib/math/math2_test
- lib/math/math_test

Fixes #56849.

Change-Id: Iea72eeb39a80e00c023b780c185b4fabe549c568
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/390860
Reviewed-by: Slava Egorov <[email protected]>
Commit-Queue: Ömer Ağacan <[email protected]>

Author: osa1

sdk/lib/_internal/wasm_js_compatibility/lib/int_patch.dart

@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:_internal' show EfficientLengthIterable, patch;
+import 'dart:_internal' show EfficientLengthIterable, patch, unsafeCast;
 import 'dart:_js_helper' as js;
 import 'dart:_js_types';
 import 'dart:_string';
@@ -100,3 +100,10 @@ class String {
         WasmI32.fromInt(end - index)));
   }
 }
+
+extension _StringExt on String {
+  int firstNonWhitespace() =>
+      unsafeCast<JSStringImpl>(this).firstNonWhitespace();
+
+  int lastNonWhitespace() => unsafeCast<JSStringImpl>(this).lastNonWhitespace();
+}

sdk/lib/_internal/wasm_js_compatibility/lib/string_patch.dart

@@ -207,9 +207,9 @@
           "_internal/wasm/lib/core_patch.dart",
           "_internal/wasm/lib/date_patch_patch.dart",
           "_internal/wasm/lib/int_common_patch.dart",
+          "_internal/wasm/lib/int_patch.dart",
           "_internal/wasm/lib/sync_star_patch.dart",
           "_internal/wasm/lib/weak_patch.dart",
-          "_internal/wasm_js_compatibility/lib/int_patch.dart",
           "_internal/wasm_js_compatibility/lib/string_buffer_patch.dart",
           "_internal/wasm_js_compatibility/lib/string_patch.dart"
         ]

sdk/lib/libraries.json

@@ -182,9 +182,9 @@ wasm_js_compatibility:
         - _internal/wasm/lib/core_patch.dart
         - _internal/wasm/lib/date_patch_patch.dart
         - _internal/wasm/lib/int_common_patch.dart
+        - _internal/wasm/lib/int_patch.dart
         - _internal/wasm/lib/sync_star_patch.dart
         - _internal/wasm/lib/weak_patch.dart
-        - _internal/wasm_js_compatibility/lib/int_patch.dart
         - _internal/wasm_js_compatibility/lib/string_buffer_patch.dart
         - _internal/wasm_js_compatibility/lib/string_patch.dart
     typed_data: