RFR: 8367899: compiler/c2/gvn/TestBitCompressValueTransform.java intermittent timed out [v2]

[SendaoYan]

> Hi all,
> 
> After JDK-8260555 change the timeout factor from 4 to 1, make test compiler/c2/gvn/TestBitCompressValueTransform.java intermittent timed out.
> 
> There are 20 10k/20k loop count of loops in this test, this cause test need many CPU cycles to finish. If I reduce the loop count from 10k/20k to 100/200, the test failures descripted in [JDK-8350896](https://bugs.openjdk.org/browse/JDK-8350896) also reproduced when the tested jdk is jdk25u. So it seems that there no need so many loop count for these tests.
> 
> Without the proposed change, the driver action finish about 65 sencods on linux-x64, with the proposed change the driver action finish about 1.5 seconds.

SendaoYan has updated the pull request incrementally with one additional commit since the last revision:

  Remove the loop which do not use the loop variable i or do not use random number

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/27548/files
  - new: https://git.openjdk.org/jdk/pull/27548/files/a916d7d3..3fabfeca

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27548&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27548&range=00-01

  Stats: 12 lines in 1 file changed: 0 ins; 9 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/27548.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27548/head:pull/27548

PR: https://git.openjdk.org/jdk/pull/27548