libobjc: run testcases with Apple runtime as well

[Dominique Dhumieres]

Nicola,

At revision 168254 on powerpc-apple-darwin9 and x86_64-apple-darwin10,
I see the following failures with -m64 (the tests pass with -m32):

FAIL: objc.dg/gnu-api-2-class.m -fnext-runtime execution test
FAIL: objc.dg/gnu-api-2-ivar.m -fnext-runtime execution test
FAIL: objc.dg/gnu-api-2-method.m -fnext-runtime execution test
FAIL: objc.dg/gnu-api-2-objc.m -fnext-runtime execution test
FAIL: objc.dg/gnu-api-2-object.m -fnext-runtime execution test
FAIL: objc.dg/gnu-api-2-protocol.m -fnext-runtime execution test

and the same ones for obj-c++.dg.

Cheers,

Dominique