[Darwin] Patch, take 2: enable linkonce support for Darwin

[Mike Stump]

On Monday, February 2, 2004, at 02:55 PM, Matt Austern wrote:
>>> OK!  As you may have noticed, version 3 of my patch avoids COMMON
>>> on all platforms where ONE_ONLY is available.
>>
>> I can't help but wonder if this results in larger .o files (ls -l 
>> type sizes), or slower compiles...  and how big of an effect it is.
>
> Slower compile, I can't think of any reason to wonder that.  Larger .o 
> files...  Conceivably it could increase or decrease the size of the .o 
> files, but the effect is almost certainly negligible.  The compiler 
> currently uses COMMON for C++ vague linkage only in a few pretty rare 
> cases.

Ah, sorry, I was thinking of the change that did this by default for 
all languages (including C), as C has the same problem that C++ does on 
darwin about dylibs and common, not your change.