hg: jdk/jdk12: 8215575: C2 crash: assert(get_instanceKlass()->is_loaded()) failed: must be at least loaded

[coleen.phillimore at oracle.com]

Changeset: b11483a74e5d
Author:    coleenp
Date:      2019-01-09 07:52 -0500
URL:       http://hg.openjdk.java.net/jdk/jdk12/rev/b11483a74e5d

8215575: C2 crash: assert(get_instanceKlass()->is_loaded()) failed: must be at least loaded
Summary: Set InstanceKlass::loaded before adding classes to the subklass list, which can be read concurrently by the compiler.
Reviewed-by: dholmes, eosterlund

! src/hotspot/share/classfile/systemDictionary.cpp
! src/hotspot/share/oops/instanceKlass.cpp
! src/hotspot/share/oops/instanceKlass.hpp