Add operators test to source_mapping_test.

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

Index: pkg/compiler/lib/src/cps_ir/cps_fragment.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_fragment.dart b/pkg/compiler/lib/src/cps_ir/cps_fragment.dart
index 6eda70742528e37e653693eee459ff277fda8980..fbc7f37c450131c04873c179d03a5a0ad7f86224 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_fragment.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_fragment.dart
@@ -109,7 +109,7 @@ class CpsFragment {
 
   /// Invoke a built-in operator.
   Primitive applyBuiltin(BuiltinOperator op, List<Primitive> args) {
-    return letPrim(new ApplyBuiltinOperator(op, args));
+    return letPrim(new ApplyBuiltinOperator(op, args, sourceInformation));
   }
 
   /// Inserts an invocation. binds its continuation, and returns the
@@ -258,10 +258,10 @@ class CpsFragment {
   }
 
   /// Puts the given fragment into this one.
-  /// 
+  ///
   /// If [other] was an open fragment, its hole becomes the new hole
   /// in this fragment.
-  /// 
+  ///
   /// [other] is reset to an empty fragment after this.
   void append(CpsFragment other) {
     if (other.root == null) return;