[objc-gnustep] Don't emit .guess ivar offset vars.
[objc-gnustep] Don't emit .guess ivar offset vars.

These were intended to allow non-fragile and fragile ABI code to be
mixed, as long as the fragile classes were higher up the hierarchy than
the non-fragile ones.  Unfortunately:

 - No one actually wants to do this.
 - Recent versions of Linux's run-time linker break it.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@339128 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang