Revert "Refactor handling of compounds."

pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart

Index: pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart
diff --git a/pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart b/pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart
index a57db7e337c6e4d5a9ee00916007efcc48fdec04..3505c861f79f116c11b7b62ddc3e3e9496344b84 100644
--- a/pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart
+++ b/pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart
@@ -1007,8 +1007,8 @@ class SimpleTypeInferrerVisitor<T>
   @override
   T visitSuperCompoundIndexSet(
       ast.SendSet node,
-      MethodElement getter,
-      MethodElement setter,
+      FunctionElement getter,
+      FunctionElement setter,
       ast.Node index,
       op.AssignmentOperator operator,
       ast.Node rhs,
@@ -1020,7 +1020,6 @@ class SimpleTypeInferrerVisitor<T>
   T visitUnresolvedSuperGetterCompoundIndexSet(
       ast.SendSet node,
       Element element,
-      MethodElement setter,
       ast.Node index,
       op.AssignmentOperator operator,
       ast.Node rhs,
@@ -1031,7 +1030,7 @@ class SimpleTypeInferrerVisitor<T>
   @override
   T visitUnresolvedSuperSetterCompoundIndexSet(
       ast.SendSet node,
-      MethodElement getter,
+      FunctionElement getter,
       Element element,
       ast.Node index,
       op.AssignmentOperator operator,
@@ -1044,7 +1043,6 @@ class SimpleTypeInferrerVisitor<T>
   T visitUnresolvedSuperGetterIndexPrefix(
       ast.SendSet node,
       Element element,
-      MethodElement setter,
       ast.Node index,
       op.IncDecOperator operator,
       _) {
@@ -1055,7 +1053,7 @@ class SimpleTypeInferrerVisitor<T>
   @override
   T visitUnresolvedSuperSetterIndexPrefix(
       ast.SendSet node,
-      MethodElement getter,
+      FunctionElement getter,
       Element element,
       ast.Node index,
       op.IncDecOperator operator,
@@ -1068,7 +1066,6 @@ class SimpleTypeInferrerVisitor<T>
   T visitUnresolvedSuperGetterIndexPostfix(
       ast.SendSet node,
       Element element,
-      MethodElement setter,
       ast.Node index,
       op.IncDecOperator operator,
       _) {
@@ -1079,7 +1076,7 @@ class SimpleTypeInferrerVisitor<T>
   @override
   T visitUnresolvedSuperSetterIndexPostfix(
       ast.SendSet node,
-      MethodElement getter,
+      FunctionElement getter,
       Element element,
       ast.Node index,
       op.IncDecOperator operator,