[PATCH] [compiler-rt] Don't instrument globals from __objc_classname

[Kuba Brecka]

>>! In D6488#17, @majnemer wrote:
> Why does `ShouldInstrumentGlobal` need a triple argument?  `GlobalVariable` has a `getParent` method which will return the `Module`.

Because `Module` only stores the triple as a string, and I wanted to avoid parsing the string for every single global.

http://reviews.llvm.org/D6488