RFR (XL) 8155672: Remove instanceKlassHandles and KlassHandles

[coleen.phillimore at oracle.com]

Summary: Use unhandled pointers for Klass and InstanceKlass, remove 
handles with no implementation.

These are fairly extensive changes.  The KlassHandle types have been 
dummy types since permgen elimination and were thought to be useful for 
future features.  They aren't, so can be removed (see bug for more 
details).   This allows stricter typing because you can use the more 
specific type, and using const more.  I didn't add const to these 
changes, because of the cascading effect.

The change isn't hard to review, just tedious.  The main bug that I had 
was redeclaring a type inside a scope, and InstanceKlass::cast(k) can't 
take a NULL k, whereas instanceKlassHandle ik(THREAD, k) could.

It's so nice being able to single step on gdb without going into 
KlassHandle constructors!

open webrev at http://cr.openjdk.java.net/~coleenp/8155672.01/webrev
bug link https://bugs.openjdk.java.net/browse/JDK-8155672

Tested with all hotspot jtreg tests, java/lang/invoke tests, 
java/lang/instrument tests, all closed tonga colocated tests, and JPRT.

I can continue to hold this change for a convenient time for merging 
purposes with other people's JDK10 changes that they've been holding, or 
if there are other jdk9 changes that are likely to cause a problem for 
merging.  I'll update the copyrights to 2017 on commit.

Thanks,
Coleen