RFR: Fix array base addressing after merge

[Roman Kennke]

I made a mistake in last merge: asserts in objArrayKlass have been
firing and I 'fixed' it by ripping out the resolve() barrier in
arrayOopDesc::base(). However, that breaks all the places which call
*_at_addr() and still need the resolve() barrier. The correct fix is to
restore the resolve() barrier and use at_addr_raw() in objArrayKlass.

http://cr.openjdk.java.net/~rkennke/fix-array-base/webrev.00/

Ok?

Test: tier3_gc_shenandoah ok

Roman