RFR [XS] : 8218562: handle HOTSPOT_BUILD_COMPILER for clang/xlclang and cleanup HOTSPOT_BUILD_COMPILER settings

[David Holmes]

Hi Matthias,

On 7/02/2019 1:17 am, Baesken, Matthias wrote:
> Hello, please review this small change .
> 
> I noticed (when looking into AIX xlc16 / xlclang++)  the following:    in the case that  clang is used for compilation,    HOTSPOT_BUILD_COMPILER   claims to be a gcc .
> This is a bit misleading.
> This change  adjusts the setting for clang usage on  AIX  (for future usage with xlclang++)   and macOSX.
> 
> Additionally I removed some  old  HOTSPOT_BUILD_COMPILER   for  legacy Oracle / Sun Studio versions ).

Possibly more could be removed :)

Changes seem fine.

I've always been irked by the fact we can access an actual version 
string from the compilers themselves, so we wouldn't need this code.

Thanks,
David

> 
> Bug/webrev :
> 
> https://bugs.openjdk.java.net/browse/JDK-8218562
> 
> http://cr.openjdk.java.net/~mbaesken/webrevs/8218562.0/
> 
> 
> Thanks, Matthias
>