RFR: 8257181: s390x builds are very noisy with gc-sections messages

[Aleksey Shipilev]

Sample build log sizes:

PPC64 fastdebug, 200 kilobytes:
   https://builds.shipilev.net/openjdk-jdk/build-logs/build-linux-ppc64le-fastdebug.log

S390X fastdebug, 20 megabytes!
   https://builds.shipilev.net/openjdk-jdk/build-logs/build-linux-s390x-server-fastdebug.log

S390X slowdebug, 200 megabytes!
   https://builds.shipilev.net/openjdk-jdk/build-logs/build-linux-s390x-server-slowdebug.log

JDK-8234525 enabled `gc-sections`. We can and should disable `print-gc-sections` to get sane build logs back.

Additional testing:
 - [x] Linux s390x fastdebug cross-compilation

-------------

Commit messages:
 - 8257181: s390x builds are very noisy with gc-sections messages

Changes: https://git.openjdk.java.net/jdk/pull/1459/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1459&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8257181
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1459.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1459/head:pull/1459

PR: https://git.openjdk.java.net/jdk/pull/1459