RFR: 8368793: java/lang/StringBuilder/RacingSBThreads.java timed out in Xcomp subtest [v2]

[Roger Riggs]

> Instead of raising the timeout, leave the execution of the -Xcomp tests to higher tiers in the CI.
> Remove the explicit -Xcomp run.

Roger Riggs has updated the pull request incrementally with one additional commit since the last revision:

  There is no need for an explicit extra -Xcomp run.
  Later tiers of the CI testing run with -Xcomp and raise the timeouts when they do.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/27531/files
  - new: https://git.openjdk.org/jdk/pull/27531/files/97d4a336..a7689583

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27531&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27531&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/27531.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27531/head:pull/27531

PR: https://git.openjdk.org/jdk/pull/27531