Request for reviews (S): 6782232: assert("CreateEx must be first instruction in block" )

[Vladimir Kozlov]

http://webrev.invokedynamic.info/kvn/6782232/index.html

Fixed 6782232: assert("CreateEx must be first instruction in block" )

Problem:
The check for CreateEx is missing in the code which adds
MachSpillCopy nodes to a block.

Solution:
- Add the missing check for CreateEx.
- Add new notproduct flag VerifyRegisterAllocator to check
   graph integrity during RA. It helped to find this bug.
   VerifyOpto has a lot of false positive asserts during
   IGVN optimizations which currently prevents its usage
   during RA.
- Fix verification code in method verify_base_ptrs()
   to check all Phi's paths and type of derived and base
   pointers.

Reviewed by:
Fix verified (y/n): y

Other testing:
JPRT, CTW (with VerifyRegisterAllocator)