dart2js cps: Remove NonTailThrow.

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

Index: pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
index a299237f326529584d964337fadc09de1ee85715..c29f2bfaa2f461b3ddf167f317c663a91e27c29f 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
@@ -339,11 +339,6 @@ class IRTracer extends TracerUtil implements cps_ir.Visitor {
         "${node.arguments.map(formatReference).join(', ')}";
   }
 
-  visitNonTailThrow(cps_ir.NonTailThrow node) {
-    String value = formatReference(node.value);
-    return "NonTailThrow($value)";
-  }
-
   visitCreateInvocationMirror(cps_ir.CreateInvocationMirror node) {
     String args = node.arguments.map(formatReference).join(', ');
     return "CreateInvocationMirror(${node.selector.name}, $args)";
@@ -619,10 +614,6 @@ class BlockCollector implements cps_ir.Visitor {
     unexpectedNode(node);
   }
 
-  visitNonTailThrow(cps_ir.NonTailThrow node) {
-    unexpectedNode(node);
-  }
-
   visitCreateInvocationMirror(cps_ir.CreateInvocationMirror node) {
     unexpectedNode(node);
   }