RFR: 8293287 add ReplayReduce flag

[Dean Long]

Add an experimental flag to help developers "reduce" a replay file.

As a first step, I plan to simulate reduced inlining. This will output multiple "compile" lines as if the first level of inlining never happened:
A --> B --> C
A --> D --> E
becomes
B --> C
D --> E
Developers can repeat iteratively until the replay crash no longer reproduces.

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Commit messages:
 - first pass at ReplayReduce

Changes: https://git.openjdk.org/jdk/pull/10134/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10134&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293287
  Stats: 46 lines in 8 files changed: 39 ins; 2 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/10134.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10134/head:pull/10134

PR: https://git.openjdk.org/jdk/pull/10134