Revert "[dartdevc] fix for const / overridden fields"

This is breaking Flutter Web - see:

flutter/flutter#40876

Will need to reopen: #38455

Change-Id: I6942cdc136533286c3a5eee93439d4f0f9beb28b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/118261
Reviewed-by: Vijay Menon <vsm@google.com>
Reviewed-by: Mark Zhou <markzipan@google.com>
Commit-Queue: Vijay Menon <vsm@google.com>

Author: vsmenon

pkg/dev_compiler/lib/src/compiler/shared_compiler.dart

@@ -252,7 +252,6 @@ abstract class SharedCompiler<Library, Class, InterfaceType, FunctionNode> {
     /// runtime call.
     js_ast.TemporaryId initPrivateNameSymbol() {
       var idName = name.endsWith('=') ? name.replaceAll('=', '_') : name;
-      idName = idName.replaceAll('.', '_');
       var id = js_ast.TemporaryId(idName);
       moduleItems.add(js.statement('const # = #.privateName(#, #)',
           [id, runtimeModule, emitLibraryName(library), js.string(name)]));
@@ -263,16 +262,6 @@ abstract class SharedCompiler<Library, Class, InterfaceType, FunctionNode> {
     return privateNames.putIfAbsent(name, initPrivateNameSymbol);
   }
 
-  /// Emits a private name JS Symbol for [name] unique to a Dart class [cls].
-  ///
-  /// This is now required for fields of constant objects that may be
-  /// overridden within the same library.
-  @protected
-  js_ast.TemporaryId emitClassPrivateNameSymbol(
-      Library library, String className, String memberName) {
-    return emitPrivateNameSymbol(library, '$className.$memberName');
-  }
-
   /// Emits an expression to set the property [nameExpr] on the class [className],
   /// with [value].
   ///

pkg/dev_compiler/lib/src/kernel/compiler.dart

@@ -2796,9 +2796,10 @@ class ProgramCompiler extends ComputeOnceConstantVisitor<js_ast.Expression>
 
   void _emitVirtualFieldSymbols(Class c, List<js_ast.Statement> body) {
     _classProperties.virtualFields.forEach((field, virtualField) {
-      var symbol = emitClassPrivateNameSymbol(
-          c.enclosingLibrary, getLocalClassName(c), field.name.name);
-      body.add(js.statement('const # = #;', [virtualField, symbol]));
+      body.add(js.statement('const # = Symbol(#);', [
+        virtualField,
+        js.string('${getLocalClassName(c)}.${field.name.name}')
+      ]));
     });
   }
 
@@ -5407,15 +5408,8 @@ class ProgramCompiler extends ComputeOnceConstantVisitor<js_ast.Expression>
     entryToProperty(MapEntry<Reference, Constant> entry) {
       var constant = visitConstant(entry.value);
       var member = entry.key.asField;
-      var cls = member.enclosingClass;
-      // Enums cannot be overridden, so we can safely use the field name
-      // directly.  Otherwise, use a private symbol in case the field
-      // was overridden.
-      var symbol = cls.isEnum
-          ? _emitMemberName(member.name.name, member: member)
-          : emitClassPrivateNameSymbol(
-              cls.enclosingLibrary, getLocalClassName(cls), member.name.name);
-      return js_ast.Property(symbol, constant);
+      return js_ast.Property(
+          _emitMemberName(member.name.name, member: member), constant);
     }
 
     var type = visitInterfaceType(node.getType(_types) as InterfaceType);

pkg/dev_compiler/lib/src/kernel/property_model.dart

@@ -161,13 +161,6 @@ class _LibraryVirtualFieldModel {
       if (_extensiblePrivateClasses.contains(class_)) return true;
     }
 
-    if (class_.constructors.any((c) => c.isConst)) {
-      // Always virtualize fields of a (might be) non-enum (see above) const
-      // class.  The way these are lowered by the CFE, they need to be
-      // writable from different modules even if overridden.
-      return true;
-    }
-
     // Otherwise, the field is effectively private and we only need to make it
     // virtual if it's overridden.
     return _overriddenPrivateFields.contains(field);