Request for reviews (M): 6873116: Modify reexecute implementation to use pcDesc to record the reexecute bit

[changpeng fang - Sun Microsystems - Santa Clara United States]

http://cr.openjdk.java.net/~cfang/6873116/webrev.00/

Fixed 6873116:  Modify reexecute implementation to use pcDesc to record 
the reexecute bit

The implementation in this work is mostly from Christian's work on 
reexecute/mh bit changes.

Problem:
Current implementation of reexecute bit uses DebugInfoStreams to record 
the reexecute bit by compressing the reexecute bit
into bci field. This makes the code look ugly 
(e.g.read_bci_and_reexecute(bool& reexecute). It also makes the future 
addition
of debuginfo difficult.

Solution:
In this work, we use pcDesc to record the reexecute bit obtained from 
describe_scope, and then store the reexecute bit to
scopeDesc when a scopeDesc object is created.

Tests:
  JPRT, CompileTheWord, refworkload

Thanks,

Changpeng