ART: Add some reflection cutouts

Add Class.getInnerClassFlags and Method.invoke to unstarted runtime.

Allows to compile-time initialize:
* android.net.NetworkInfo
* android.net.wifi.WifiInfo

Bug: 27265238

(cherry picked from commit b3ffbe32b78c18739736fc998d65430b46c510e5)

Change-Id: I3e267519acf14b08c687f1e831e2027d37158767
diff --git a/runtime/mirror/class.cc b/runtime/mirror/class.cc
index 42f003d..b4a23ba 100644
--- a/runtime/mirror/class.cc
+++ b/runtime/mirror/class.cc
@@ -1165,5 +1165,16 @@
     mirror::Class* klass,
     mirror::ObjectArray<mirror::Class>* args);
 
+int32_t Class::GetInnerClassFlags(Handle<Class> h_this, int32_t default_value) {
+  if (h_this->IsProxyClass() || h_this->GetDexCache() == nullptr) {
+    return default_value;
+  }
+  uint32_t flags;
+  if (!h_this->GetDexFile().GetInnerClassFlags(h_this, &flags)) {
+    return default_value;
+  }
+  return flags;
+}
+
 }  // namespace mirror
 }  // namespace art