RFR: 8303082 : [AIX] Missing C++ name demangling with XLClang++ [v5]

[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 incrementally with 475 additional commits since the last revision:

 - 8303082 : [AIX] Missing C++ name demangling with XLClang++
 - 8305520: ToggleNotifyJvmtiTest.java fails with release VMs
   
   Reviewed-by: sspitsyn
 - 8173709: Fix VerifyLoopOptimizations - step 1 - minimal infrastructure
   
   Reviewed-by: kvn, chagedorn, thartmann
 - 8304996: Add missing HandleMarks
   
   Reviewed-by: coleenp, shade, iklam
 - 8303278: Imprecise bottom type of ExtractB/UB
   
   Reviewed-by: qamai, thartmann
 - 8297286: runtime/vthread tests crashing after JDK-8296324
   
   Reviewed-by: lmesnik, pchilanomate, cjplummer
 - 8305206: Add @spec tags in java.base/java.* (part 1)
   
   Reviewed-by: alanb, naoto, darcy, lancea, dfuchs, iris, mchung
 - 8303798: REDO - Remove fdlibm C sources
   
   Reviewed-by: alanb, iris, jwaters, erikj, kvn, dholmes
 - 8305421: Work around JDK-8305420 in CDSJDITest.java
   
   Reviewed-by: cjplummer
 - 8304743: Compile_lock and SystemDictionary updates
   
   Reviewed-by: vlivanov, dholmes, dlong
 - ... and 465 more: https://git.openjdk.org/jdk/compare/1b05a7df...bd602ab9

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/12742/files
  - new: https://git.openjdk.org/jdk/pull/12742/files/1b05a7df..bd602ab9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12742&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12742&range=03-04

  Stats: 375234 lines in 2980 files changed: 221835 ins; 129818 del; 23581 mod
  Patch: https://git.openjdk.org/jdk/pull/12742.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/12742/head:pull/12742

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