AllocateHeapAt disabling on AIX

[Aleksey Shipilev]

On 09/26/2018 06:09 PM, David Holmes wrote:
> On 26/09/2018 12:02 PM, Baesken, Matthias wrote:
>> Hi David,  I would like to  print something like  "AllocateHeapAt  not supported on AIX" .
>> And then exit   (probably just ignoring the flag and printing the message might be bad ).
>>
>> The constraint functions were suggested to me as an option but  it looks to me they are
>> Intended for other use cases .
> 
> Yes, I think a check in argument.cpp would be better.

There is already a similar block there at L3848:

#if defined(_ALLBSD_SOURCE) || defined(AIX)  // UseLargePages is not yet supported on BSD and AIX.
  UNSUPPORTED_OPTION(UseLargePages);
#endif

...I think you can add the AllocateHeapAt check nearby, Matthias.

-Aleksey