Add operators test to source_mapping_test.

pkg/compiler/lib/src/js_backend/codegen/unsugar.dart

Index: pkg/compiler/lib/src/js_backend/codegen/unsugar.dart
diff --git a/pkg/compiler/lib/src/js_backend/codegen/unsugar.dart b/pkg/compiler/lib/src/js_backend/codegen/unsugar.dart
index bbe998f1f396f742fb02e2570ed10aa6e2a32156..332e07b5cf21454dbd9f094f09102a1cb8fc314d 100644
--- a/pkg/compiler/lib/src/js_backend/codegen/unsugar.dart
+++ b/pkg/compiler/lib/src/js_backend/codegen/unsugar.dart
@@ -127,7 +127,8 @@ class UnsugarVisitor extends RecursiveVisitor {
     Primitive nullPrimitive = nullConstant;
     Primitive test = new ApplyBuiltinOperator(
         BuiltinOperator.Identical,
-          <Primitive>[function.parameters.single, nullPrimitive]);
+          <Primitive>[function.parameters.single, nullPrimitive],
+          function.parameters.single.sourceInformation);
 
     Expression newBody =
         new LetCont.many(<Continuation>[returnFalse, originalBody],
@@ -158,8 +159,8 @@ class UnsugarVisitor extends RecursiveVisitor {
     Selector selector = new Selector.fromElement(function);
     // TODO(johnniwinther): Come up with an implementation of SourceInformation
     // for calls such as this one that don't appear in the original source.
-    InvokeStatic invoke =
-        new InvokeStatic(function, selector, arguments, continuation, null);
+    InvokeStatic invoke = new InvokeStatic(
+        function, selector, arguments, continuation, null);
     _parentVisitor.processInvokeStatic(invoke);
 
     LetCont letCont = new LetCont(continuation, invoke);
@@ -245,7 +246,8 @@ class UnsugarVisitor extends RecursiveVisitor {
       Set<ClassElement> interceptedClasses =
         _glue.getInterceptedClassesOn(selector);
       _glue.registerSpecializedGetInterceptor(interceptedClasses);
-      newReceiver = new Interceptor(receiver, interceptedClasses);
+      newReceiver = new Interceptor(
+          receiver, interceptedClasses, node.sourceInformation);
       insertLetPrim(newReceiver, node);
     }
 
@@ -274,7 +276,8 @@ class UnsugarVisitor extends RecursiveVisitor {
     Primitive t = trueConstant;
     Primitive i = new ApplyBuiltinOperator(
         BuiltinOperator.Identical,
-        <Primitive>[condition.value.definition, t]);
+        <Primitive>[condition.value.definition, t],
+        condition.value.definition.sourceInformation);
     LetPrim newNode = new LetPrim(t,
         new LetPrim(i,
             new Branch(new IsTrue(i),