[jdk11u-dev] RFR: 8217233: Update build settings for AIX/xlc [v3]

[Tyler Steele]

> Discovered while bringing xlc 16.1 support to jdk11. This change adds stack protection to AIX and cleans up the flags to apply #998.
> 
> Reviewed-by: clanger, sgroeger
> 
> Backport Conflicts:
> - minor conflict in flags-cflags.m4 (potentially caused by comment
> addition?)

Tyler Steele has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains two commits:

 - Remove comment picked up from backport
 - 8217233: Update build settings for AIX/xlc
   
   Reviewed-by: clanger, sgroeger
   
   Backport Conflicts:
   - minor conflict in flags-cflags.m4 (potentially caused by comment
   addition?)

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

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/1030/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=1030&range=02
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/1030.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/1030/head:pull/1030

PR: https://git.openjdk.java.net/jdk11u-dev/pull/1030