WindowsError.str should display the windows error code,
not the posix error code; with test.
Fixes #1576174.

Backported from trunk, revision 52485.
diff --git a/Misc/NEWS b/Misc/NEWS
index 57e5ad0..9ad45fc 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
 Core and builtins
 -----------------
 
+- Bug #1576174: WindowsError now displays the windows error code
+  again, no longer the posix error code.
+
 - Patch #1549049: Support long values in structmember.
 
 - Bug #1542016: make sys.callstats() match its docstring and return an