Use the app snapshot when testing with -cdartk.

runtime/vm/snapshot.cc

Index: runtime/vm/snapshot.cc
diff --git a/runtime/vm/snapshot.cc b/runtime/vm/snapshot.cc
index 97f0d847dcd9e5a7d89a2614a1cbcede2bab1937..84ef21f7c2af9df56e5cc8fff4f6ec4f8f81cc67 100644
--- a/runtime/vm/snapshot.cc
+++ b/runtime/vm/snapshot.cc
@@ -182,6 +182,59 @@ const Snapshot* Snapshot::SetupFromBuffer(const void* raw_memory) {
 }
 
 
+const char* Snapshot::FeaturesString(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.
+    Isolate* isolate = Isolate::Current();
+    buffer.AddString(isolate->asserts() ? " asserts" : " no-asserts");
+    buffer.AddString(isolate->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();
+}
+
+
 RawSmi* BaseReader::ReadAsSmi() {
   intptr_t value = Read<int32_t>();
   ASSERT((value & kSmiTagMask) == kSmiTag);
@@ -639,7 +692,7 @@ RawApiError* SnapshotReader::VerifyVersionAndFeatures() {
   }
   Advance(version_len);
 
-  const char* expected_features = Dart::FeaturesString(kind_);
+  const char* expected_features = Snapshot::FeaturesString(kind_);
   ASSERT(expected_features != NULL);
   const intptr_t expected_len = strlen(expected_features);
 
@@ -1842,7 +1895,7 @@ void SnapshotWriter::WriteVersionAndFeatures() {
   const intptr_t version_len = strlen(expected_version);
   WriteBytes(reinterpret_cast<const uint8_t*>(expected_version), version_len);
 
-  const char* expected_features = Dart::FeaturesString(kind_);
+  const char* expected_features = Snapshot::FeaturesString(kind_);
   ASSERT(expected_features != NULL);
   const intptr_t features_len = strlen(expected_features);
   WriteBytes(reinterpret_cast<const uint8_t*>(expected_features),