Parameterize TypeSystem by its node kind

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

Index: pkg/compiler/lib/src/inferrer/type_graph_nodes.dart
diff --git a/pkg/compiler/lib/src/inferrer/type_graph_nodes.dart b/pkg/compiler/lib/src/inferrer/type_graph_nodes.dart
index d7bd3cf865fcbfab6235eef0f2fd143e56a06067..cf76bf66b1898e052fb150aefc22dde04e591868 100644
--- a/pkg/compiler/lib/src/inferrer/type_graph_nodes.dart
+++ b/pkg/compiler/lib/src/inferrer/type_graph_nodes.dart
@@ -1755,13 +1755,14 @@ class ValueInMapTypeInformation extends InferredTypeInformation {
  * A [PhiElementTypeInformation] is an union of
  * [ElementTypeInformation], that is local to a method.
  */
-class PhiElementTypeInformation extends TypeInformation {
-  final ast.Node branchNode;
-  final bool isLoopPhi;
+class PhiElementTypeInformation<T> extends TypeInformation {
+  final T branchNode;
   final Local variable;
+  final bool isTry;
 
-  PhiElementTypeInformation(MemberTypeInformation context, this.branchNode,
-      this.isLoopPhi, this.variable)
+  PhiElementTypeInformation(
+      MemberTypeInformation context, this.branchNode, this.variable,
+      {this.isTry})
       : super(context);
 
   TypeMask computeType(InferrerEngine inferrer) {
@@ -1841,8 +1842,8 @@ abstract class TracedTypeInformation implements TypeInformation {
   }
 }
 
-class AwaitTypeInformation extends TypeInformation {
-  final ast.Node _node;
+class AwaitTypeInformation<T> extends TypeInformation {
+  final T _node;
 
   AwaitTypeInformation(MemberTypeInformation context, this._node)
       : super(context);
@@ -1859,8 +1860,8 @@ class AwaitTypeInformation extends TypeInformation {
   }
 }
 
-class YieldTypeInformation extends TypeInformation {
-  final ast.Node _node;
+class YieldTypeInformation<T> extends TypeInformation {
+  final T _node;
 
   YieldTypeInformation(MemberTypeInformation context, this._node)
       : super(context);