allow .abi3t.so extensions

Author: ngoldbaum

Python/dynload_shlib.c

@@ -44,7 +44,10 @@ const char *_PyImport_DynLoadFiletab[] = {
 #ifdef ALT_SOABI
     "." ALT_SOABI ".so",
 #endif
+#ifndef Py_GIL_DISABLED
     ".abi" PYTHON_ABI_STRING ".so",
+#endif  /* Py_GIL_DISABLED */
+    ".abi" PYTHON_ABI_STRING "t.so",
     ".so",
 #endif  /* __CYGWIN__ */
     NULL,