[PATCH] Add additional __builtin_unreachable() test.

[Paolo Bonzini]

>> Go ahead after changing this:
>>
>> /* { dg-options "-O2 -m32 -fomit-frame-pointer" } */
>>
>> to:
>>
>> /* { dg-require-effective-target ilp32 } */
>> /* { dg-options "-O2 -fomit-frame-pointer" } */
>>
> 
> Why?  Making that change results in the test being UNSUPPORTED on x86_64.

But not all gcc builds on x86_64 are biarch 32-bit/64-bit (though it's 
the default).  Usually what you do is test both -m32 and -m64, and that 
change will make the test UNSUPPORTED in the -m64 run, and PASS :-) in 
the -m32 run.

Paolo