RFR: 8295191: IR framework timeout options expect ms instead of s [v4]

[Eric Nothum]

> The flags `-DTestCompilationTimeout` and `-DWaitForCompilationTimeout` expect values in ms. The example in the README was misleading as one could infer from "default: 10s" that the flag expects values in ms. Therefore I changed the values and units in the example to ms.

Eric Nothum has updated the pull request incrementally with one additional commit since the last revision:

  Changed variable name for CustomRunTest.java

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Changes:
  - all: https://git.openjdk.org/jdk/pull/14649/files
  - new: https://git.openjdk.org/jdk/pull/14649/files/bee55417..dc2b46fb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14649&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14649&range=02-03

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/14649.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14649/head:pull/14649

PR: https://git.openjdk.org/jdk/pull/14649