RFR: 8256535: C2: randomize CCP processing order for stress testing

[Roberto Castañeda Lozano]

Add `StressCCP` option to randomize the selection of the node to be examined in each CCP iteration.

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Commit messages:
 - Add missing bug reference
 - 8256535: C2: randomize CCP processing order for stress testing

Changes: https://git.openjdk.java.net/jdk/pull/1765/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1765&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8256535
  Stats: 265 lines in 8 files changed: 146 ins; 114 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1765.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1765/head:pull/1765

PR: https://git.openjdk.java.net/jdk/pull/1765