Request for reviews (S): 6711117: Assertion in 64bit server vm (flat != TypePtr::BOTTOM,"cannot alias-analyze an untyped ptr")

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/6711117/webrev.00

Fixed 6711117: Assertion in 64bit server vm (flat != TypePtr::BOTTOM,"cannot alias-analyze an untyped ptr")

Problem:
The assert is triggered by the eliminate AutoBox code which asks
an alias type of "NULL+off" address type.
It is caused by the memory node processing during IGVN before
its control edge which checks the address's nullness is processed.

Solution:
Delay a memory node transformation if its control on IGVN worklist.
Delay a memory node transformation if its address on IGVN worklist.
Execute the eliminate AutoBox code only when the address is not NULL.
Use replace_node() instead of subsume_node() during macro nodes
expansion to put users of the old node on IGVN worklist.

Reviewed by:

Fix verified (y/n): y, bug test

Other testing:
JPRT