Issue #10914: Initialize correctly the filesystem codec when creating a new
subinterpreter to fix a bootstrap issue with codecs implemented in Python, as
the ISO-8859-15 codec.

Add fscodec_initialized attribute to the PyInterpreterState structure.
diff --git a/Misc/NEWS b/Misc/NEWS
index 25b316c..e993ace 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,10 @@
 Core and Builtins
 -----------------
 
+- Issue #10914: Initialize correctly the filesystem codec when creating a new
+  subinterpreter to fix a bootstrap issue with codecs implemented in Python, as
+  the ISO-8859-15 codec.
+
 - Issue #11918: OS/2 and VMS are no more supported because of the lack of
   maintainer.