Fix issue 13942 - Dart_Error function invokes OS::VSNPrint with the "format" string containing data…

runtime/bin/builtin_nolib.cc

Index: runtime/bin/builtin_nolib.cc
===================================================================
--- runtime/bin/builtin_nolib.cc	(revision 28804)
+++ runtime/bin/builtin_nolib.cc	(working copy)
@@ -22,17 +22,19 @@
 
 
 Dart_Handle Builtin::Source(BuiltinLibraryId id) {
-  return Dart_NewApiError("Unreachable code in Builtin::Source (%d).", id);
+  return DartUtils::NewError("Unreachable code in Builtin::Source (%d).", id);
 }
 
 
 Dart_Handle Builtin::PartSource(BuiltinLibraryId id, const char* uri) {
-  return Dart_NewApiError("Unreachable code in Builtin::PartSource (%d).", id);
+  return DartUtils::NewError(
+      "Unreachable code in Builtin::PartSource (%d).", id);
 }
 
 
 Dart_Handle Builtin::GetSource(const char** source_paths, const char* uri) {
-  return Dart_NewApiError("Unreachable code in Builtin::GetSource (%s).", uri);
+  return DartUtils::NewError(
+      "Unreachable code in Builtin::GetSource (%s).", uri);
 }