RFR (L): 8035857: Add tests to verify correctness of operations with BMI1 and LZCNT instructions

[Filipp Zhinkin]

Hi all,

I'd like to add new tests that verifies correctness of code that
use BMI1 and LZCNT instructions.

Tests executed in two JVM processes - one started in Xint mode
and other in Xcomp. Results obtained from these processes compared
and tests pass only if results are equal.

Despite the fact that there is a test on
{Integer,Long}::{numberOfLeadingZeros,numberOfTrailingZeros} intrinsics
(compiler/6823354/Test6823354.java), I've added test cases to cover it
too in order to verify that everything works fine with explicitly specified
+UseCountTrailingZerosInstruction and +UseCountLeadingZerosInstruction.

Test execution will be skipped if CPU on test box does not support
required features. In order to check supported features new WB method
was added. WhiteBox::getCPUFeatures() return VM_Version::cpu_features()
string, which is parsed in order to gather CPU features.

Webrev: http://cr.openjdk.java.net/~iignatyev/fzhinkin/8035857/webrev.00/
Testing: JPRT, manual, automated.

Thanks,
Filipp.