RFR(XS): 8005114: VM is crashing in ciKlass*ciObjArrayKlass::element_klass() if metaspaces are full

[Roland Westrelin]

The VM runs out of metaspace. As a consequence, in a c1 compilation, ciEnv::_unloaded_ciobjarrayklass is used for an array klass. LoadIndexed::declared_type() tries to find the element_type of this klass. LoadIndexed::declared_type() should test whether the klass is loaded. 

http://cr.openjdk.java.net/~roland/8005114/webrev.00/

Roland.