Stop linking with crt1.o etc. for the iOS simulator. <rdar://problem/11800973>

Recent versions of the iOS simulator no longer require linking with the
crt1.o, dylib1.o, or bundle1.o files. The relevant code is now included in
libSystem for the simulator.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199696 91177308-0d34-0410-b5e6-96231b3b80d8