[PATCH] [Sanitizer] Update GetMaxVirtualAddress for PowerPC64 Linux

[Jay Foad]

>>! In D6082#9, @willschm wrote:
> Roughly half of the systems I'm running on are old enough that they use the 44-bit address space, so I would prefer to allow those to continue working.  :-)     At least until they fail for some other difficult reason, at least. 

Fair enough. In that case I humbly withdraw this patch; let's go with D6044 instead. It sounds like you're best placed to test this stuff anyway, Will.

http://reviews.llvm.org/D6082