RFR: 8349375: Cleanup AIX special file build settings

[Matthias Baesken]

The special optimization settings for  jvmtiEnterTrace.cpp on AIX can be removed ; the file compiles now some seconds with or without this workaround.
The special settings were needed for ancient versions of xlC.

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

Commit messages:
 - JDK-8349375

Changes: https://git.openjdk.org/jdk/pull/23487/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23487&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349375
  Stats: 7 lines in 1 file changed: 0 ins; 7 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/23487.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23487/head:pull/23487

PR: https://git.openjdk.org/jdk/pull/23487