Automatically add build definition Py_DEBUG, when building module for debug build of Python.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>

siputils.py

@@ -856,6 +856,13 @@ class Makefile:
 
         cppflags = []
 
+        if getattr(sys, "pydebug", False):
+            cppflags.append("-DPy_DEBUG")
+
+        if hasattr(sys, "abiflags"):
+            if 'd' in sys.abiflags:
+                cppflags.append("-DPy_DEBUG")
+
         if not self._debug:
             cppflags.append("-DNDEBUG")