dart2js cps: Support inlining constructors with type arguments.

pkg/compiler/lib/src/cps_ir/inline.dart

Index: pkg/compiler/lib/src/cps_ir/inline.dart
diff --git a/pkg/compiler/lib/src/cps_ir/inline.dart b/pkg/compiler/lib/src/cps_ir/inline.dart
index cc046eec2c56c6588041c26cee5f3c652ae5b072..024baf2bd1866896640e95d70320643bc7173ab4 100644
--- a/pkg/compiler/lib/src/cps_ir/inline.dart
+++ b/pkg/compiler/lib/src/cps_ir/inline.dart
@@ -128,13 +128,14 @@ class InliningCache {
   /// lookup result returns [NO_INLINE].  If there is no cached result,
   /// [ABSENT] is returned.
   get(ExecutableElement element, CallStructure callStructure, TypeMask receiver,
-      List<TypeMask> arguments) {
+      List<TypeMask> arguments, DartType concreteType) {
     List<CacheEntry> entries = map[element];
     if (entries != null) {
       for (CacheEntry entry in entries) {
         if (entry.match(callStructure, receiver, arguments)) {
           if (entry.decision) {
-            FunctionDefinition function = copier.copy(entry.function);
+            FunctionDefinition function = copier.copy(entry.function,
+                concreteType: concreteType);
             ParentVisitor.setParents(function);
             return function;
           }
@@ -359,7 +360,8 @@ class InliningVisitor extends TrampolineRecursiveVisitor {
   // if the call was inlined, and the inlined function body is available in
   // [_fragment].  If the call was not inlined, null is returned.
   Primitive tryInlining(InvocationPrimitive invoke, FunctionElement target,
-                        CallStructure callStructure) {
+                        CallStructure callStructure,
+                        {GenericType concreteType}) {
     // Quick checks: do not inline or even cache calls to targets without an
     // AST node, targets that are asynchronous or generator functions, or
     // targets containing a try statement.
@@ -386,7 +388,8 @@ class InliningVisitor extends TrampolineRecursiveVisitor {
         invoke.arguments.map(abstractType).toList();
     var cachedResult = _inliner.cache.get(target, callStructure,
         abstractReceiverInMethod,
-        abstractArguments);
+        abstractArguments,
+        concreteType);
 
     // Negative inlining result in the cache.
     if (cachedResult == InliningCache.NO_INLINE) return null;
@@ -523,14 +526,6 @@ class InliningVisitor extends TrampolineRecursiveVisitor {
 
   @override
   Primitive visitInvokeConstructor(InvokeConstructor node) {
-    if (node.dartType is GenericType) {
-      // We cannot inline a constructor invocation containing type arguments
-      // because CreateInstance in the body does not know the type arguments.
-      // We would incorrectly instantiate a class like A instead of A<B>.
-      // TODO(kmillikin): try to fix this.
-      GenericType generic = node.dartType;
-      if (generic.typeArguments.any((DartType t) => !t.isDynamic)) return null;
-    }
-    return tryInlining(node, node.target, null);
+    return tryInlining(node, node.target, null, concreteType: node.dartType);
   }
 }