[CodeGen] Call SetInternalFunctionAttributes to attach function

attributes to internal functions.

This patch fixes CodeGenModule::CreateGlobalInitOrDestructFunction to
use SetInternalFunctionAttributes instead of SetLLVMFunctionAttributes
to attach function attributes to internal functions.

Also, make sure the correct CGFunctionInfo is passed instead of always
passing what arrangeNullaryFunction returns.

rdar://problem/20828324

Differential Revision: http://reviews.llvm.org/D13610

llvm-svn: 251734