Fix makefile build on OSX when ARM targets are not enabled

[loladiro]

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.

[beanz]

LGTM.

Thanks for catching this!

-Chris

cfe/trunk/runtime/compiler-rt/Makefile

 IOS_SDK := $(shell xcrun --show-sdk-path -sdk iphoneos 2> /dev/null)
 IOSSIM_SDK := $(shell xcrun --show-sdk-path -sdk iphonesimulator 2> /dev/null)
 
 ifneq ($(IOS_SDK)$(IOSSIM_SDK),)
 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 \
                                  ubsan_iossim_dynamic.dylib
 endif
 
 RuntimeLibrary.macho_embedded.Configs := \
   hard_static.a hard_pic.a