py/malloc: Introduce m_tracked_calloc, m_tracked_free functions.

Enabled by MICROPY_TRACKED_ALLOC.

Signed-off-by: Damien George <damien@micropython.org>

py/misc.h

@@ -103,6 +103,13 @@ void m_free(void *ptr);
 #endif
 NORETURN void m_malloc_fail(size_t num_bytes);
 
+#if MICROPY_TRACKED_ALLOC
+// These alloc/free functions track the pointers in a linked list so the GC does not reclaim
+// them.  They can be used by code that requires traditional C malloc/free semantics.
+void *m_tracked_calloc(size_t nmemb, size_t size);
+void m_tracked_free(void *ptr_in);
+#endif
+
 #if MICROPY_MEM_STATS
 size_t m_get_total_bytes_allocated(void);
 size_t m_get_current_bytes_allocated(void);