[TSan] Ensure we can compile the runtime with older SDKs

[yln]

Summary

One of my changes [1] included in this release silently bumped the
minimal macOS SDK required for building the TSan runtime to SDK 10.12.
Let's ensure release 10 does not unexpectedly break builders with old
SDKs and add proper minimal SDK checking in CMake for subsequent
releases.

This fix #ifdefs out interceptors for newer APIs. Note that the
resulting TSan runtime is less complete: when these newer APIs are used
TSan will report false positives.

Fixes llvm 10 release blocker: #44682
https://bugs.llvm.org/show_bug.cgi?id=44682

[1] 894abb46f891cba2e0ef581650f27f512a7824b4

[yln]

I can land this as soon as @dmajor confirms that it fixes their build.

[dmajor]

The build was successful, thank you!

[yln]

Manually closing revision. Automation picked up the commit but did not close this revision; maybe because the commit was to a release branch instead of master.

[dmajor]

Thanks @yln! For posterity, the commit was rGc32d809e9cae8da7d3016b6cb30e2a2a9c9e2762 / https://github.com/llvm/llvm-project/commit/c32d809e9cae8da7d3016b6cb30e2a2a9c9e2762.

compiler-rt/lib/tsan/rtl/tsan_interceptors_mac.cpp

 #include "tsan_interceptors.h"
 #include "tsan_interface.h"
 #include "tsan_interface_ann.h"
 #include "sanitizer_common/sanitizer_addrhashmap.h"
 
 #include <errno.h>
 #include <libkern/OSAtomic.h>
 #include <objc/objc-sync.h>
-#include <os/lock.h>
 #include <sys/ucontext.h>
 
+#if defined(__has_include) && __has_include(<os/lock.h>)
+#include <os/lock.h>
+#endif
+
 #if defined(__has_include) && __has_include(<xpc/xpc.h>)
 #include <xpc/xpc.h>
 #endif  // #if defined(__has_include) && __has_include(<xpc/xpc.h>)
 
 typedef long long_t;
 
 extern "C" {
 int getcontext(ucontext_t *ucp) __attribute__((returns_twice));
TSAN_INTERCEPTOR(void, os_lock_unlock, void *lock) {
   if (!cur_thread()->is_inited) {
     return REAL(os_lock_unlock)(lock);
   }
   SCOPED_TSAN_INTERCEPTOR(os_lock_unlock, lock);
   Release(thr, pc, (uptr)lock);
   REAL(os_lock_unlock)(lock);
 }
 
+#if defined(__has_include) && __has_include(<os/lock.h>)
+
 TSAN_INTERCEPTOR(void, os_unfair_lock_lock, os_unfair_lock_t lock) {
   if (!cur_thread()->is_inited || cur_thread()->is_dead) {
     return REAL(os_unfair_lock_lock)(lock);
   }
   SCOPED_TSAN_INTERCEPTOR(os_unfair_lock_lock, lock);
   REAL(os_unfair_lock_lock)(lock);
   Acquire(thr, pc, (uptr)lock);
 }
TSAN_INTERCEPTOR(void, os_unfair_lock_unlock, os_unfair_lock_t lock) {
   if (!cur_thread()->is_inited || cur_thread()->is_dead) {
     return REAL(os_unfair_lock_unlock)(lock);
   }
   SCOPED_TSAN_INTERCEPTOR(os_unfair_lock_unlock, lock);
   Release(thr, pc, (uptr)lock);
   REAL(os_unfair_lock_unlock)(lock);
 }
 
+#endif  // #if defined(__has_include) && __has_include(<os/lock.h>)
+
 #if defined(__has_include) && __has_include(<xpc/xpc.h>)
 
 TSAN_INTERCEPTOR(void, xpc_connection_set_event_handler,
                  xpc_connection_t connection, xpc_handler_t handler) {
   SCOPED_TSAN_INTERCEPTOR(xpc_connection_set_event_handler, connection,
                           handler);
   Release(thr, pc, (uptr)connection);
   xpc_handler_t new_handler = ^(xpc_object_t object) {