Support runtime check of function types.

sdk/lib/_internal/compiler/implementation/ssa/nodes.dart

Index: sdk/lib/_internal/compiler/implementation/ssa/nodes.dart
diff --git a/sdk/lib/_internal/compiler/implementation/ssa/nodes.dart b/sdk/lib/_internal/compiler/implementation/ssa/nodes.dart
index 915908fe6da702fb71eb601c751c0f2adbb612f9..dcbf95f1f8605e8d5b187c87d41291127f139fcf 100644
--- a/sdk/lib/_internal/compiler/implementation/ssa/nodes.dart
+++ b/sdk/lib/_internal/compiler/implementation/ssa/nodes.dart
@@ -2239,6 +2239,7 @@ class HTypeConversion extends HCheck {
   final DartType typeExpression;
   final int kind;
   final Selector receiverTypeCheckSelector;
+  final bool contextIsTypeArguments;
 
   static const int NO_CHECK = 0;
   static const int CHECKED_MODE_CHECK = 1;
@@ -2250,7 +2251,8 @@ class HTypeConversion extends HCheck {
   HTypeConversion(this.typeExpression, this.kind,
                   HType type, HInstruction input,
                   [this.receiverTypeCheckSelector])
-      : super(<HInstruction>[input]) {
+      : contextIsTypeArguments = false,
+        super(<HInstruction>[input]) {
     assert(!isReceiverTypeCheck || receiverTypeCheckSelector != null);
     sourceElement = input.sourceElement;
     instructionType = type;
@@ -2259,7 +2261,18 @@ class HTypeConversion extends HCheck {
   HTypeConversion.withTypeRepresentation(this.typeExpression, this.kind,
                                          HType type, HInstruction input,
                                          HInstruction typeRepresentation)
-      : super(<HInstruction>[input, typeRepresentation]),
+      : contextIsTypeArguments = false,
+        super(<HInstruction>[input, typeRepresentation]),
+        receiverTypeCheckSelector = null {
+    sourceElement = input.sourceElement;
+    instructionType = type;
+  }
+
+  HTypeConversion.withContext(this.typeExpression, this.kind,
+                              HType type, HInstruction input,
+                              HInstruction context,
+                              {bool this.contextIsTypeArguments})
+      : super(<HInstruction>[input, context]),
         receiverTypeCheckSelector = null {
     sourceElement = input.sourceElement;
     instructionType = type;
@@ -2268,6 +2281,9 @@ class HTypeConversion extends HCheck {
   bool get hasTypeRepresentation => inputs.length > 1;
   HInstruction get typeRepresentation => inputs[1];
 
+  bool get hasContext => inputs.length > 1;
+  HInstruction get context => inputs[1];
+
   HInstruction convertType(Compiler compiler, DartType type, int kind) {
     if (typeExpression == type) return this;
     return super.convertType(compiler, type, kind);