This is preparation for PPC64 integration: http://openjdk.java.net/jeps/175
This and following ppc64 changes will go into staging repository first and tested there: http://hg.openjdk.java.net/ppc-aix-port/stage/

Implement lateExpand that expands nodes after register allocation.

http://hg.openjdk.java.net/ppc-aix-port/jdk8/hotspot/file/df79d76c17ab/ppc_patches/0115_8003850_opto-introduce_phase_lateExpand.patch

We proposed this change before:
http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2012-November/008909.html
 
The lateExpand phase in the C2 compiler expands nodes after Register allocation.
Some nodes can not be expanded during matching. E.g., register allocation
might not be able to deal with the resulting pattern. To allow better
scheduling in such cases, we introduce lateExpand which runs after
register allocation. Whether and how nodes are expanded is specified
in the ad-file. See block.cpp for a detailed documentation. We use this
for some nodes on ppc, and extensively on ia64.
  
In the mail cited above you find an example how to use late expand for the sparc.ad file.
and you see the code generated by adlc.