Fix which Darwin versions have ObjC runtime with full subscripting support.

[vsapsai]

Summary

Update min deployment target in some tests so that they don't try
to link against libarclite and don't fail when it's not available.

rdar://problem/29253617

[kubamracek]

Great! So the versions in ObjCRuntime.h didn't really match what the iOS and macOS supported?

[vsk]

Thanks for digging into and addressing this!

[vsapsai]

In D43787#1019886, @kubamracek wrote:

Great! So the versions in ObjCRuntime.h didn't really match what the iOS and macOS supported?

Yes, support for assigning nil for a key for NSMutableDictionary was added in macOS 10.11, iOS 9. Earlier versions require libarclite.

compiler-rt/trunk/test/lit.common.cfg

try:
     if output_re:
       cpu_subtype = int(output_re.group(1))
       if cpu_subtype == 8: # x86_64h
         config.available_features.add('x86_64h')
   except:
     pass
 
   config.substitutions.append( ("%macos_min_target_10_11", "-mmacosx-version-min=10.11") )
+
+  isIOS = getattr(config, 'ios', False)
+  # rdar://problem/22207160
+  config.substitutions.append( ("%darwin_min_target_with_full_runtime_arc_support",
+      "-miphoneos-version-min=9.0" if isIOS else "-mmacosx-version-min=10.11") )
 else:
   config.substitutions.append( ("%macos_min_target_10_11", "") )
+  config.substitutions.append( ("%darwin_min_target_with_full_runtime_arc_support", "") )
 
 if config.android:
   adb = os.environ.get('ADB', 'adb')
   try:
     android_api_level_str = subprocess.check_output([adb, "shell", "getprop", "ro.build.version.sdk"]).rstrip()
   except (subprocess.CalledProcessError, OSError):
     lit_config.fatal("Failed to read ro.build.version.sdk (using '%s' as adb)" % adb)
   try:

compiler-rt/trunk/test/tsan/Darwin/norace-objcxx-run-time.mm

-// RUN: %clang_tsan %s -lc++ -fobjc-arc -lobjc -o %t -framework Foundation
+// RUN: %clang_tsan %s -lc++ -fobjc-arc -lobjc -o %t -framework Foundation %darwin_min_target_with_full_runtime_arc_support
 // RUN: %run %t 2>&1 | FileCheck %s
 
 // Check that we do not report races between:
 // - Object retain and initialize
 // - Object release and dealloc
 // - Object release and .cxx_destruct
 
 #import <Foundation/Foundation.h>