RFR: JMH Pre-Integration Tests workflow [v3]

[Aleksey Shipilev]

> This adds the basic pre-integration test workflow for the project.

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

  Add JDK 7, disable some excessive configurations from testing

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Changes:
  - all: https://git.openjdk.java.net/jmh/pull/5/files
  - new: https://git.openjdk.java.net/jmh/pull/5/files/fa39616f..80de40e6

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jmh&pr=5&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jmh&pr=5&range=01-02

  Stats: 8 lines in 1 file changed: 4 ins; 2 del; 2 mod
  Patch: https://git.openjdk.java.net/jmh/pull/5.diff
  Fetch: git fetch https://git.openjdk.java.net/jmh pull/5/head:pull/5

PR: https://git.openjdk.java.net/jmh/pull/5