Roll dart_style 2.0.0 into the repo.

There are no formatting changes aside from adding support for generic
metadata annotations, which are not yet used. Changes are:

- Migrated to null safety.
- Return exit code from FormatCommand.run().

Change-Id: I8892f6551541f673b8e49045665e2371ba40b026
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/191182
Commit-Queue: Jake Macdonald <jakemac@google.com>
Reviewed-by: Nate Bosch <nbosch@google.com>

.dart_tool/package_config.json

@@ -11,7 +11,7 @@
     "constraint, update this by running tools/generate_package_config.dart."
   ],
   "configVersion": 2,
-  "generated": "2021-03-12T09:00:31.497265",
+  "generated": "2021-03-15T10:48:35.022974",
   "generator": "tools/generate_package_config.dart",
   "packages": [
     {
@@ -220,7 +220,7 @@
       "name": "dart_style",
       "rootUri": "../third_party/pkg_tested/dart_style",
       "packageUri": "lib/",
-      "languageVersion": "2.9"
+      "languageVersion": "2.12"
     },
     {
       "name": "dartdev",
@@ -695,13 +695,13 @@
       "name": "test_descriptor",
       "rootUri": "../third_party/pkg/test_descriptor",
       "packageUri": "lib/",
-      "languageVersion": "2.0"
+      "languageVersion": "2.12"
     },
     {
       "name": "test_process",
       "rootUri": "../third_party/pkg/test_process",
       "packageUri": "lib/",
-      "languageVersion": "2.0"
+      "languageVersion": "2.12"
     },
     {
       "name": "test_reflective_loader",

DEPS

@@ -98,7 +98,7 @@ vars = {
   #     and land the review.
   #
   # For more details, see https://github.com/dart-lang/sdk/issues/30164
-  "dart_style_tag": "1.3.11",  # Please see the note above before updating.
+  "dart_style_tag": "a1d65dd9c4b83c9702ba409465879b94caeb04ea",
 
   "chromedriver_tag": "83.0.4103.39",
   "dartdoc_rev" : "174021f3d76c2a8500b54977c80f32c5bbc099f1",
@@ -155,8 +155,8 @@ vars = {
   "stream_channel_tag": "d7251e61253ec389ee6e045ee1042311bced8f1d",
   "string_scanner_rev": "1b63e6e5db5933d7be0a45da6e1129fe00262734",
   "sync_http_rev": "b59c134f2e34d12acac110d4f17f83e5a7db4330",
-  "test_descriptor_tag": "1.1.1",
-  "test_process_tag": "1.0.3",
+  "test_descriptor_tag": "2.0.0",
+  "test_process_tag": "2.0.0",
   "term_glyph_rev": "6a0f9b6fb645ba75e7a00a4e20072678327a0347",
   "test_reflective_loader_rev": "54e930a11c372683792e22bddad79197728c91ce",
   "test_rev": "e673623f45d75ccec750d35271b0b4d1423e9fac",

pkg/front_end/testcases/generic_metadata/generic_metadata.dart.textual_outline.expect

@@ -1,15 +1,19 @@
 class A<T> {
   const A();
 }
+
 class B<S, T> {
   const B();
 }
+
 class C<T extends num> {
   const C();
 }
+
 class D<S extends num, T extends S> {
   const D();
 }
+
 @A<int, num>()
 @B<int>()
 @C<String>()

pkg/front_end/testcases/generic_metadata/generic_metadata.dart.textual_outline_modelled.expect

@@ -0,0 +1,32 @@
+class A<T> {
+  const A();
+}
+
+class B<S, T> {
+  const B();
+}
+
+class C<T extends num> {
+  const C();
+}
+
+class D<S extends num, T extends S> {
+  const D();
+}
+
+@A()
+@A<int>()
+@B()
+@B<int, String>()
+@C()
+@C<num>()
+@C<int>()
+@D()
+@D<num, num>()
+@D<num, int>()
+main() {}
+@A<int, num>()
+@B<int>()
+@C<String>()
+@D<int, num>()
+test() {}

pkg/front_end/testcases/textual_outline.status

@@ -62,7 +62,6 @@ general/null_safety_invalid_experiment: FormatterCrash
 general/null_safety_invalid_experiment_and_language_version: FormatterCrash
 general/type_parameters_on_void: FormatterCrash
 general/var_as_type_name: FormatterCrash
-generic_metadata/generic_metadata: FormatterCrash
 inference/unsafe_block_closure_inference_function_call_explicit_dynamic_param_via_expr1: FormatterCrash
 inference/unsafe_block_closure_inference_function_call_explicit_type_param_via_expr1: FormatterCrash
 late_lowering/covariant_late_field: FormatterCrash