Add type inference for assignment to local variables.

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

Index: pkg/front_end/lib/src/fasta/kernel/body_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index 08211e9a64dbe5fbddaebff2da66286607f3ff04..e6b717b69ed8ba10693dd5cb80941e5dd6cd615b 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -3100,7 +3100,8 @@ abstract class ContextAccessor extends FastaAccessor {
   Expression buildCompoundAssignment(Name binaryOperator, Expression value,
       {int offset: TreeNode.noOffset,
       bool voidContext: false,
-      Procedure interfaceTarget}) {
+      Procedure interfaceTarget,
+      bool isPreIncDec: false}) {
     return makeInvalidWrite(value);
   }