runtime: delete native/java_lang_Runtime.cc

We're now using Runtime.c from ojluni, which does the same set
of things via the JVM interface. This removes unnecessary duplication
of code between Runtime.cc and OpenJdkJvm.cc.

Also includes a few changes to JVM_NativeLoad to bring it in sync
with the version in Runtime.cc.

bug: 27387202
Change-Id: I92aac81d131661aca588e352aee7a167593e17d4
diff --git a/runtime/openjdkjvm/OpenjdkJvm.cc b/runtime/openjdkjvm/OpenjdkJvm.cc
index d377457..aff9b61 100644
--- a/runtime/openjdkjvm/OpenjdkJvm.cc
+++ b/runtime/openjdkjvm/OpenjdkJvm.cc
@@ -342,15 +342,15 @@
 
   // Starting with N nativeLoad uses classloader local
   // linker namespace instead of global LD_LIBRARY_PATH
-  // (23 is Marshmallow)
-  if (target_sdk_version <= 23) {
+  // (23 is Marshmallow). This call is here to preserve
+  // backwards compatibility for the apps targeting sdk
+  // version <= 23
+  if (target_sdk_version == 0) {
     SetLdLibraryPath(env, javaLibrarySearchPath);
   }
 
   std::string error_msg;
   {
-    art::ScopedObjectAccess soa(env);
-    art::StackHandleScope<1> hs(soa.Self());
     art::JavaVMExt* vm = art::Runtime::Current()->GetJavaVM();
     bool success = vm->LoadNativeLibrary(env,
                                          filename.c_str(),