[LSan] Add the way to disable LSan at link time

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@185066 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/sanitizer/lsan_interface.h b/include/sanitizer/lsan_interface.h
index c826323..97a88a5 100644
--- a/include/sanitizer/lsan_interface.h
+++ b/include/sanitizer/lsan_interface.h
@@ -25,6 +25,10 @@
   void __lsan_enable();
   // The heap object into which p points will be treated as a non-leak.
   void __lsan_ignore_object(const void *p);
+  // The user may optionally provide this function to disallow leak checking
+  // for the program it is linked into. Note: this function may be called late,
+  // after all the global destructors.
+  int __lsan_is_turned_off();
 #ifdef __cplusplus
 }  // extern "C"