[CMake][Apple-stage2] Don't link with -fno-pie
[CMake][Apple-stage2] Don't link with -fno-pie

On Darwin the default is to build PIC and link PIE. We shouldn't need to override that in the Apple Clang distributions.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@268642 91177308-0d34-0410-b5e6-96231b3b80d8

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