Use the app snapshot when testing with -cdartk.

runtime/vm/dart.cc

Index: runtime/vm/dart.cc
diff --git a/runtime/vm/dart.cc b/runtime/vm/dart.cc
index 916e81bb14824779a26edcc42172197091448e00..65b5b3c33d2ffe04c3c08362744aea228b1d6382 100644
--- a/runtime/vm/dart.cc
+++ b/runtime/vm/dart.cc
@@ -637,58 +637,6 @@ RawError* Dart::InitializeIsolate(const uint8_t* snapshot_data,
 }
 
 
-const char* Dart::FeaturesString(Snapshot::Kind kind) {
-  TextBuffer buffer(64);
-
-// Different fields are included for DEBUG/RELEASE/PRODUCT.
-#if defined(DEBUG)
-  buffer.AddString("debug");
-#elif defined(PRODUCT)
-  buffer.AddString("product");
-#else
-  buffer.AddString("release");
-#endif
-
-  if (Snapshot::IncludesCode(kind)) {
-    // Checked mode affects deopt ids.
-    buffer.AddString(FLAG_enable_asserts ? " asserts" : " no-asserts");
-    buffer.AddString(FLAG_enable_type_checks ? " type-checks"
-                                             : " no-type-checks");
-
-// Generated code must match the host architecture and ABI.
-#if defined(TARGET_ARCH_ARM)
-#if defined(TARGET_ABI_IOS)
-    buffer.AddString(" arm-ios");
-#elif defined(TARGET_ABI_EABI)
-    buffer.AddString(" arm-eabi");
-#else
-#error Unknown ABI
-#endif
-    buffer.AddString(TargetCPUFeatures::hardfp_supported() ? " hardfp"
-                                                           : " softfp");
-#elif defined(TARGET_ARCH_ARM64)
-    buffer.AddString(" arm64");
-#elif defined(TARGET_ARCH_MIPS)
-    buffer.AddString(" mips");
-#elif defined(TARGET_ARCH_IA32)
-    buffer.AddString(" ia32");
-#elif defined(TARGET_ARCH_X64)
-#if defined(_WIN64)
-    buffer.AddString(" x64-win");
-#else
-    buffer.AddString(" x64-sysv");
-#endif
-#elif defined(TARGET_ARCH_DBC)
-    buffer.AddString(" dbc");
-#elif defined(TARGET_ARCH_DBC64)
-    buffer.AddString(" dbc64");
-#endif
-  }
-
-  return buffer.Steal();
-}
-
-
 void Dart::RunShutdownCallback() {
   Isolate* isolate = Isolate::Current();
   void* callback_data = isolate->init_callback_data();