RFR: 8272720: Fix the implementation of loop unrolling heuristic with LoopPercentProfileLimit

[Jie Fu]

Hi all,

I'd like to fix the implementation of loop unrolling heuristic with `LoopPercentProfileLimit`.

The range of `LoopPercentProfileLimit` was designed as [10, 100] [1].
But in fact there is no difference when `LoopPercentProfileLimit > 50` for the current implementation.

This is because integer div `100 / LoopPercentProfileLimit` [2] will always return 1 when `LoopPercentProfileLimit > 50`.
It would be better to fix it.

Thanks.
Best regards,
Jie

[1] https://github.com/openjdk/jdk/blob/master/src/hotspot/share/opto/c2_globals.hpp#L179
[2] https://github.com/openjdk/jdk/blob/master/src/hotspot/share/opto/loopTransform.cpp#L908

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Commit messages:
 - 8272720: Fix the implementation of loop unrolling heuristic with LoopPercentProfileLimit

Changes: https://git.openjdk.java.net/jdk/pull/5183/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5183&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8272720
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5183.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5183/head:pull/5183

PR: https://git.openjdk.java.net/jdk/pull/5183