The __weak and __strong defines are common to all darwin targets
and are even set in C mode.  As such, move them to Targets.cpp.

__OBJC_GC__ is also darwin specific, but seems reasonable to always
define it when in objc-gc mode.

This fixes rdar://6761450


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68494 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed