RFR: JDK-8258484: AIX build fails in Harfbuzz with XLC 16.01.0000.0006 [v2]

[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.

Matthias Baesken has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains two new commits since the last revision:

 - Adjust comment
 - JDK-8258484

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1972/files
  - new: https://git.openjdk.java.net/jdk/pull/1972/files/ecd93d06..27205b26

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1972&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1972&range=00-01

  Stats: 2 lines in 1 file changed: 1 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