Request for reviews (S): 7178280: Failed new vector regression tests

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/7178280/webrev

7178280: Failed new vector regression tests

Post-Allocation copy removal optimization incorrectly replaced spill copy with 
previously loaded register which was already modified by an other vector 
operation with smaller vector size.

When looking for the same value in an other register check that all parts of 
that register has the same value.

Also removed unused line.

Tested with failing and other regression tests.

Thanks,
Vladimir