[pkg:js] Disable JS/Native class conflict check

Bug: #44778

The Native/JS class conflict check breaks user behavior. It should
instead be added under a language version to avoid a breakage on
SDK update. This CL simply disables the check always so that it can
be a simpler cherry-pick for 2.12.

Change-Id: I40b0a3a4c46b1442257028c99360ef0ed0b4154c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/181440
Reviewed-by: Riley Porter <[email protected]>
Reviewed-by: Sigmund Cherem <[email protected]>
Commit-Queue: Srujan Gaddam <[email protected]>

Author: srujzs

pkg/_js_interop_checks/lib/js_interop_checks.dart

@@ -30,6 +30,9 @@ class JsInteropChecks extends RecursiveVisitor<void> {
   bool _classHasAnonymousAnnotation = false;
   bool _libraryHasJSAnnotation = false;
   bool _libraryIsGlobalNamespace = false;
+  // TODO(srujzs): This currently disables this check always. This check should
+  // instead only be disabled up until a given language version.
+  bool _disableJSNativeClassConflict = true;
 
   JsInteropChecks(
       this._coreTypes, this._diagnosticsReporter, this._nativeClasses);
@@ -83,7 +86,8 @@ class JsInteropChecks extends RecursiveVisitor<void> {
             cls.location.file);
       }
     }
-    if (_classHasJSAnnotation &&
+    if (!_disableJSNativeClassConflict &&
+        _classHasJSAnnotation &&
         !_classHasAnonymousAnnotation &&
         _libraryIsGlobalNamespace) {
       var jsClass = getJSName(cls);