[PATCH][darwin] revert to .weak_definition on darwin<10

[Iain Sandoe]

Hi Jim,
On 10 Dec 2013, at 00:17, Jim Grosbach wrote:
>> 
>> We can then key codegen on the correct thing.
>> 
>> ISTM that when a compiler is "inherently a cross compiler" *and* is under development *and* might be used with a bunch of different exterior tools, that passing the linker and assembler version to the codegen is a sensible step (at least during the development phase).
> 
> Having the compiler output be used by a bunch of different exterior tools has never been a goal before. It’s always been required to use a “recent enough” binutils/cctools+ld64.

Hmm. well, I can imagine this being useful even if one was only covering the "last two editions of binutils on various platforms" + ld64 &&|| lld on the native platform ..

.. which was why i suggested it - however, certainly not an intention to jump through hoops to achieve it.

> You guys are in a tricky spot, though, working on a platform that realistically can’t get new low level tools (other than what clang itself builds/ships with).

well, the alternative is to back-port a "sufficiently modern" ld64/as set to the system(s) we want to support .. it's also under consideration - the down side is that anyone wanting to adopt clang on such a system then has to build a bunch more stuff (not sure that's a biggie but…).
Iain