Request for reviews (XS): 6869822: assert(Universe::narrow_oop_shift() == 0,"use unscaled narrow oop")

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/6869822/webrev.00

Fixed 6869822: assert(Universe::narrow_oop_shift() == 0,"use unscaled narrow oop")

Problem:
The test uses -XX:HeapBaseMinAddress=32g flag to force heap allocation
above 32g and get compressed oops with non zero base.
In such case the finction Universe::preferred_heap_base() sets
narrow_oop_shift to 3 and returns 0 as requested heap address.
But with 0 requested address (default memory address request) OS still may
allocate small heap bellow 4gb. And this will trigger the assert.

Solution:
Replace the assert with narrow_oop_shift set to 0.
Also use specified on command line HeapBaseMinAddress value as
heap base address for the first (from three) request.

Reviewed by:

Fix verified (y/n): y, bug's tests

Other testing:
JPRT