Build 32 bit binaries on amd64

["C. Bergström"]

On 08/21/12 09:32 AM, Dan McGregor wrote:
> Hi.
>
> I've been working on porting compiler-rt/clang's support for address
> sanitization (asan) to FreeBSD.  So far I have it building and it
> appears to work properly, however the build system expects to be able
> to build 32 bit binaries on amd64.
>
> amd64 doesn't include i386's machine/foo headers.  The included patch
> is my proposed solution:
>
> Add i386 headers to /usr/include/i386, and in machine/foo.h, check if
> it's a 32 bit build and include the appropriate header from i386.
>
> For example machine/ucontext.h will include i386/ucontext.h if
> compiled with -m32.
>
> Thoughts?
>
> If anyone's curious about the compiler_rt port, I have it at
> github.com/dannomac/compiler-rt on the branch named freebsd.
Sorry for fencepost comment which may have no/little relevance here

Changing the hierarchy to ISA/bits may make cross compiling easier in 
the future