[Lazarus] IDE Macro for # of bits of the Source OS? (eg. 32-bit/64-bit -- A $(SrcCPU) would be nice!)

[Den]

Hello all,

     Is there a convenient way using Package "Conditionals" (Options -> 
Other) to detect if the SOURCE Operating System is 32bit/64bit? Kinda 
like $(TargetCPU) but a $(SrcCPU)?

Thanks!

- Dennis Fehr