This reverts commit e5143062; not sure what
problems exactly it was supposed to work around, but at least a "make check"
against Apple's Clang "Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM
3.2svn)" on Mac OS X 10.8 works flawlessly.

Conflicts:
	configure.in

Change-Id: Ib7c80dd29e9e7a92b90be3919cd097b7e64883a1