Fix makefile build on OSX when ARM targets are not enabled

Summary: When LLVM/Clang is built without ARM support, the ios_kext runtime
library is not built, but without this patch, the Makefile still tries to
copy it. This is a recent regression, because the ios_kext library used
to also be built on x86_64.

Reviewers: beanz

Subscribers: aemerson, cfe-commits, rengolin

Differential Revision: http://reviews.llvm.org/D13421

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@249281 91177308-0d34-0410-b5e6-96231b3b80d8

runtime/compiler-rt/Makefile

@@ -89,8 +89,10 @@ RuntimeLibrary.darwin.Configs += ios.a profile_ios.a
 endif
 
 ifneq ($(IOS_SDK),)
+ifneq (,$(filter ARM AARCH64,$(TARGETS_TO_BUILD)))
 RuntimeLibrary.darwin.Configs += cc_kext_ios.a
 endif
+endif
 
 ifneq ($(IOSSIM_SDK),)
 RuntimeLibrary.darwin.Configs += asan_iossim_dynamic.dylib \