Request for reviews (S): 6788376: allow to ignore unrecognized VM options

[Vladimir Kozlov]

It was finally approved by CCC so I'm resending it before the push.

http://webrev.invokedynamic.info/kvn/6788376/index.html

Fixed 6788376: allow to ignore unrecognized VM options

Problem:
Hotspot has flags which could be unavailable in different
VM versions (server vs client, product vs debug).
It complicates VM testing.

Solution:
Add new product flag -XX:+IgnoreUnrecognizedVMOptions to allow
ignore unrecognized VM options and execute a java program.
By default it is off.

Add the flag to the test compiler/6775880/Test.java
to run it with product VM (DeoptimizeALot flag is
the debug flag unavailable in product VM).

Reviewed by: ysr, xlu
Fix verified (y/n): y

Other testing:
JPRT