[Lazarus] patch for rx.inc define linux_darwin definition

[Marco van de Voort]

On Thu, Feb 26, 2015 at 05:06:51PM +0200, FreeMan wrote:
> I added patch for rx using in osx
> this is just add "Linux_Darwin" compiler directive in rx.inc file.
> If you want use this, You have to change "Linux_Darwin" with {$...... 
> LINUX} I mean, change "LINUX" to "Linux_Darwin". original rx code just 
> use compiler directive if linux .... else ...    else for windows
> TRxDBLookupCombo when click button, grind create on behind form and can 
> not access it.

Better use:

{$ifdef unix} // FPC  all *nixes including Linux,Darwin, *BSD and Solaris
 {$define Linux_Darwin}
{$endif}

{$ifdef Linux}              // legacy Kylix
 {$define Linux_Darwin}
{$endif}