[patch i386]:Ensure intrinsic functions are declared "C"

[Jason Merrill]

On 05/12/2010 10:02 AM, Richard Guenther wrote:
>> The issue, which occures here is, that a user wants - for example - to
>> include <xmmintrin.h>  header in C++. Now he includes afterwards for
>> windows the math.h/intrin.h (which both have explicit C language
>> scope). What happens here? A bunch of warnings/failures caused by C++
>> vs. C language scope.
>> So why we shouldn't care?
>
> You'll get ODR violation errors anyway in that case.

I don't think so.  If the Windows header just has declarations, they can 
merge just fine with the xmmintrin.h definitions -- if they have the 
right language linkage.

You'd only get an ODR violation if you have a class/enum/inline/template 
defined in multiple translation units that uses the intrinsics but 
sometimes sees the definitions in xmmintrin and sometimes not.

Jason