Change IncompleteErrorGenerator to make use of NonLValueGenerator.

This allows the special-case assignment handler methods to be removed
from ErroneousExpressionGenerator.

Change-Id: Iaf957f756dca56298c9ed49c6093fabe5ffd4149
Reviewed-on: https://dart-review.googlesource.com/66720
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>

pkg/front_end/lib/src/fasta/kernel/expression_generator.dart

@@ -81,7 +81,6 @@ import 'kernel_ast_api.dart'
         TypeParameterType,
         UnresolvedTargetInvocationJudgment,
         UnresolvedVariableAssignmentJudgment,
-        UnresolvedVariableUnaryJudgment,
         VariableDeclaration;
 
 import 'kernel_builder.dart'
@@ -888,57 +887,6 @@ abstract class ErroneousExpressionGenerator implements Generator {
         isNullAware: isNullAware);
   }
 
-  @override
-  Expression buildAssignment(Expression value, {bool voidContext: false}) {
-    return new SyntheticExpressionJudgment(buildError(
-        forest.arguments(<Expression>[value], token),
-        isSetter: true));
-  }
-
-  @override
-  Expression buildCompoundAssignment(Name binaryOperator, Expression value,
-      {int offset: -1,
-      bool voidContext: false,
-      Procedure interfaceTarget,
-      bool isPreIncDec: false}) {
-    return new SyntheticExpressionJudgment(buildError(
-        forest.arguments(<Expression>[value], token),
-        isGetter: true));
-  }
-
-  @override
-  Expression buildPrefixIncrement(Name binaryOperator,
-      {int offset: -1, bool voidContext: false, Procedure interfaceTarget}) {
-    var error = buildError(
-        forest.arguments(
-            <Expression>[forest.literalInt(1, null)..fileOffset = offset],
-            token),
-        isGetter: true);
-    return new UnresolvedVariableUnaryJudgment(error, token)
-      ..fileOffset = offset;
-  }
-
-  @override
-  Expression buildPostfixIncrement(Name binaryOperator,
-      {int offset: -1, bool voidContext: false, Procedure interfaceTarget}) {
-    var error = buildError(
-        forest.arguments(
-            <Expression>[forest.literalInt(1, null)..fileOffset = offset],
-            token),
-        isGetter: true);
-    return new UnresolvedVariableUnaryJudgment(error, token)
-      ..fileOffset = offset;
-  }
-
-  @override
-  Expression buildNullAwareAssignment(
-      Expression value, DartType type, int offset,
-      {bool voidContext: false}) {
-    return new SyntheticExpressionJudgment(buildError(
-        forest.arguments(<Expression>[value], token),
-        isSetter: true));
-  }
-
   @override
   Expression buildSimpleRead() => new SyntheticExpressionJudgment(
       buildError(forest.argumentsEmpty(token), isGetter: true));
@@ -947,13 +895,6 @@ abstract class ErroneousExpressionGenerator implements Generator {
   Expression makeInvalidRead() => new SyntheticExpressionJudgment(
       buildError(forest.argumentsEmpty(token), isGetter: true));
 
-  @override
-  Expression makeInvalidWrite(Expression value) {
-    return new SyntheticExpressionJudgment(buildError(
-        forest.arguments(<Expression>[value], token),
-        isSetter: true));
-  }
-
   @override
   Expression invokeConstructor(List<DartType> typeArguments, String name,
       Arguments arguments, Token nameToken, Constness constness) {

pkg/front_end/lib/src/fasta/kernel/kernel_expression_generator_impl.dart

@@ -172,7 +172,7 @@ class IncompleteErrorGenerator extends IncompleteSendGenerator
       : super(helper, token, null);
 
   @override
-  Generator asLvalue() => this;
+  Generator asLvalue() => makeNonLValueGenerator();
 
   String get debugName => "IncompleteErrorGenerator";