RFR (XS): 8019247: SIGSEGV in compiled method c8e.e.t_.getArray(Ljava/lang/Class; )[Ljava/lang/Object

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/8019247/webrev/

Undo recent changes (and add more comments) which were looking innocent 
but broke hidden dependency on it in Parse::array_store_check() which 
checks allocation klass.
When allocation done by reflection the type of klass node used by 
AllocateArray node is general j.l.Object.class. As result the code in 
array_store_check() treat the allocation as instance instead of array 
and loads values from j.l.Object klass instead of corresponding array's 
klass.

Tested with failed test, jtreg, ctw, jprt.

Thanks,
Vladimir