Add missing SIRT to LoadNativeLibrary.

When we transition to kWaitingForJniOnLoad, we are suspended and
a GC can occur. This caused issues since classloaders are movable.

Change-Id: Iae59019c22ac64322a82300107d06a4323ee602b
diff --git a/runtime/runtime.cc b/runtime/runtime.cc
index d070207..bcd3d31 100644
--- a/runtime/runtime.cc
+++ b/runtime/runtime.cc
@@ -1087,7 +1087,8 @@
     std::string mapped_name(StringPrintf(OS_SHARED_LIB_FORMAT_STR, "javacore"));
     std::string reason;
     self->TransitionFromSuspendedToRunnable();
-    if (!instance_->java_vm_->LoadNativeLibrary(mapped_name, NULL, &reason)) {
+    SirtRef<mirror::ClassLoader> class_loader(self, nullptr);
+    if (!instance_->java_vm_->LoadNativeLibrary(mapped_name, class_loader, &reason)) {
       LOG(FATAL) << "LoadNativeLibrary failed for \"" << mapped_name << "\": " << reason;
     }
     self->TransitionFromRunnableToSuspended(kNative);