RFR: JDK-8258484: AIX build fails in Harfbuzz with XLC 16.01.0000.0006

[Matthias Baesken]

Hello,  for a while the AIX build fails with the following error in the harfbuzz build 
    1500-004: (U) INTERNAL COMPILER ERROR while compiling OT::MarkBasePosFormat1::collect_variation_indices(hb_collect_variation_indices_context_t *) const.
Compilation ended. Contact your Service Representative and provide the following information: GRARNN: gr29643 is used before it is defined.

This xlc 16 version is used for compiling 
bash-4.4$ xlc -qversion
IBM XL C/C++ for AIX, V16.1.0 (5725-C72, 5765-J12)
Version: 16.01.0000.0006

Solution by IBM compiler support is to use  "-qdebug=necan", this  effectively turns off an optimisation called "Early Re-canonizing" on the harfbuzz lib.

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Commit messages:
 - JDK-8258484

Changes: https://git.openjdk.java.net/jdk/pull/1972/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1972&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8258484
  Stats: 5 lines in 1 file changed: 4 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1972.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1972/head:pull/1972

PR: https://git.openjdk.java.net/jdk/pull/1972