[patch] fix PR 27948

[Danny Smith]

> 2006-06-09 Eric Christopher <echristo@apple.com>
>	* gcc.dg/bf-no-ms-layout.c: Enable for i?86-darwin.
>	* gcc.dg/bf-ms-layout.c: Ditto. Use attribute instead of
>	command line option.


We still need to test the command line option, don't we?  That is what
mingw/cygwin/interix users rely on. The bf-ms-attrib.c test was supposed
to test that the attibute did the same thing as the command line. 

Also, this should be guarded so that it compiles with native compiler,
for validation
+ #ifdef __GNUC__
#define ATTR __attribute__ ((ms_struct))
+ #endif