Merge pull request #551 from sicherha/override-nothrow-delete

Fix compatibility with GNU libstdc++ < 9

Author: daanx

include/mimalloc-new-delete.h

@@ -25,6 +25,9 @@ terms of the MIT license. A copy of the license can be found in the file
   void operator delete(void* p) noexcept              { mi_free(p); };
   void operator delete[](void* p) noexcept            { mi_free(p); };
 
+  void operator delete  (void* p, const std::nothrow_t&) noexcept { mi_free(p); }
+  void operator delete[](void* p, const std::nothrow_t&) noexcept { mi_free(p); }
+
   void* operator new(std::size_t n) noexcept(false)   { return mi_new(n); }
   void* operator new[](std::size_t n) noexcept(false) { return mi_new(n); }