[vector] RFR (S): 8250740: Crash in Compile::inline_incrementally_virtual_one()

[Vladimir Ivanov]

http://cr.openjdk.java.net/~vlivanov/panama/vector/8250740/webrev.00
https://bugs.openjdk.java.net/browse/JDK-8250740

The assert is hit when a dead call site is encountered in 
_virtual_late_inlines. It won't be cleared until cleanup pass is performed.

Instead of relaxing the assert, I refactored late inlining of virtual 
calls, so late inlining can handle direct and virtual calls in a more 
uniform fashion.

The patch is intended for vectorIntrinsics branch.

Testing: jdk/incubator/vector w/ "-ea -esa -Xcomp -XX:-TieredCompilation 
-XX:CompileThreshold=100" flags

Best regards,
Vladimir Ivanov