Remove use of compiled invoke stubs from portable.

Now the invoke stubs can be safely removed. Tested and working on ARM,
basic testing done on x86/MIPS, but portable is currently broken for them
even without the change.

Change-Id: Ib73f2b7aa9d81f5f0e1e817d16b9bec464c5a5aa
diff --git a/src/runtime.cc b/src/runtime.cc
index 1e7b000..f6fdef4 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -630,9 +630,8 @@
   CHECK(getSystemClassLoader != NULL);
 
   JValue result;
-  JValue float_result;
   ArgArray arg_array(NULL, 0);
-  InvokeWithArgArray(soa, getSystemClassLoader, &arg_array, &result, &float_result);
+  InvokeWithArgArray(soa, getSystemClassLoader, &arg_array, &result, 'L');
   mirror::ClassLoader* class_loader = down_cast<mirror::ClassLoader*>(result.GetL());
   CHECK(class_loader != NULL);