RFR: 8303082 : [AIX] Missing C++ name demangling with XLClang++ [v2]

[Deepa Kumari]

> It was failing as It was using the C++ demangling interface (Demangle) of the old demangler (that is, the C++ API as opposed to the C one). It is not supported by xlclang++ on AIX.
> To demangle names generated by xlclang++ , use cxxabi.h __cxa_demangle interface ( see cxxabi.h).
> 
> This Solution applies to the following test 
> 
> 1. SecondaryErrorTest.java`
> 2. TestSigInfoInHsErrFile.java
> 
> 
> Reported Issue : [JDK - 8303082](https://bugs.openjdk.org/browse/JDK-8303082)

Deepa Kumari has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:

 - Merge branch 'openjdk:master' into secondaryErr
 - 8303082 : [AIX] Missing C++ name demangling with XLClang++

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/12742/files
  - new: https://git.openjdk.org/jdk/pull/12742/files/a81a6889..4ed1f9d0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12742&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12742&range=00-01

  Stats: 1377 lines in 48 files changed: 619 ins; 461 del; 297 mod
  Patch: https://git.openjdk.org/jdk/pull/12742.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12742/head:pull/12742

PR: https://git.openjdk.org/jdk/pull/12742