cps-ir: Support compilation of methods that use interceptor calling convention.

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

Index: pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart
index f1e6fbb44af50141d4be27c6f756f96379c62d51..b55a8e429f903852526082dae6a203c6076c0b1d 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart
@@ -57,6 +57,10 @@ class IrBuilderTask extends CompilerTask {
   }
 
   ir.RootNode buildNode(AstElement element) {
+    return measure(() => _buildNode(element));
+  }
+
+  ir.RootNode _buildNode(AstElement element) {
     bailoutMessage = null;
     if (!canBuild(element)) {
       bailoutMessage = 'unsupported element ${element.name}:${element.kind}';