RFR: 8241187: ToolBox::grep should allow for negative filtering

[Guoxiong Li]

Hi all,

This patch adds two methods in `ToolBox` to do the negative filtering. Although the label `noreg-self` was added, I write a test for this enhancement to verify the code. And the method name `grepNotMatch` may need to be improved. Any idea is appreciated.
 
Thank you for taking the time to review.

Best Regards.

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Commit messages:
 - 8241187: ToolBox::grep should allow for negative filtering

Changes: https://git.openjdk.java.net/jdk/pull/1934/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1934&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8241187
  Stats: 80 lines in 2 files changed: 80 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1934.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1934/head:pull/1934

PR: https://git.openjdk.java.net/jdk/pull/1934