[8u20] RFR Backports of 8035735, 8028497 and 8039904

[Coleen Phillimore]

Please review backports of these bug fixes in JDK9.  Nightly testing has 
been running this code for a few nights now.

8035735: Metaspace::contains become extremely slow in some cases
Summary: Call is_metadata instead which does less work for the call in 
debugInfo.hpp which is called for all compiled code stack frames.
Reviewed-by: jmasa, dcubed

https://bugs.openjdk.java.net/browse/JDK-8035735
http://cr.openjdk.java.net/~coleenp/8035735/

(changeset applied cleanly)

8028497: SIGSEGV at ClassLoaderData::oops_do(OopClosure*, KlassClosure*, 
bool)
Summary: Keep class in CLD::_klasses list and mirror created for CDS 
classes if OOM during restore_shareable_info(). This keeps pointers 
consistent for CMS.
Reviewed-by: ehelin, stefank, jmasa, iklam

http://cr.openjdk.java.net/~coleenp/8028497_4/
https://bugs.openjdk.java.net/browse/JDK-8028497

(changeset had one difference because of name change from this_oop to 
this_k).

8039904: dtrace/hotspot/Monitors/Monitors001 fails with "assert(s > 0) 
failed: Bad size calculated"
Summary: Dtrace monitoring uses size before mirror size is set.
Reviewed-by: kamg, hseigel

http://cr.openjdk.java.net/~coleenp/8039904/
https://bugs.openjdk.java.net/browse/JDK-8039904

(changeset applied cleanly)

Thanks,
Coleen