[darwin] [builtins] Stop generating cc_kext_ios5 and move iOS architectures out of cc_kext into cc_kext_ios

[beanz]

Summary

This corresponds to a patch to compiler-rt (D13112).

Xcode 7 doesn't support targeting iOS5 and earlier. Instead of just dropping cc_kext_ios5, I've repurposed it to cc_kext_ios, and I'm pulling the iOS architectures out of cc_kext. Putting OS X and iOS slices inside the same archive was just odd.

[bob.wilson]

Good idea. The patch looks good. It will need to be coordinated with a change to compiler_rt build cc_kext_ios.a, though. Thanks for cleaning this up.

cfe/trunk/lib/Driver/ToolChains.cpp

void DarwinClang::AddCCKextLibArgs(const ArgList &Args,
   // For Darwin platforms, use the compiler-rt-based support library
   // instead of the gcc-provided one (which is also incidentally
   // only present in the gcc lib dir, which makes it hard to find).
 
   SmallString<128> P(getDriver().ResourceDir);
   llvm::sys::path::append(P, "lib", "darwin");
 
   // Use the newer cc_kext for iOS ARM after 6.0.
-  if (!isTargetIPhoneOS() || isTargetIOSSimulator() ||
-      getTriple().getArch() == llvm::Triple::aarch64 ||
-      !isIPhoneOSVersionLT(6, 0)) {
-    llvm::sys::path::append(P, "libclang_rt.cc_kext.a");
+  if (isTargetIPhoneOS()) {
+    llvm::sys::path::append(P, "libclang_rt.cc_kext_ios.a");
   } else {
-    llvm::sys::path::append(P, "libclang_rt.cc_kext_ios5.a");
+    llvm::sys::path::append(P, "libclang_rt.cc_kext.a");
   }
 
   // For now, allow missing resource libraries to support developers who may
   // not have compiler-rt checked out or integrated into their build.
   if (llvm::sys::fs::exists(P))
     CmdArgs.push_back(Args.MakeArgString(P));
 }
 

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),)
-RuntimeLibrary.darwin.Configs += cc_kext_ios5.a
+RuntimeLibrary.darwin.Configs += cc_kext_ios.a
 endif
 
 ifneq ($(IOSSIM_SDK),)
 RuntimeLibrary.darwin.Configs += asan_iossim_dynamic.dylib \
                                  ubsan_iossim_dynamic.dylib
 endif
 
 RuntimeLibrary.macho_embedded.Configs := \