Fix a pair of missed extern "C" decls.

borrowed/libc/strptime.h

@@ -25,6 +25,10 @@
 #ifndef __STRPTIME_H__
 #define __STRPTIME_H__
 
+#ifdef __cplusplus
+extern "C"
+{
+#endif
 /*
  * Version of "strptime()", for the benefit of OSes that don't have it.
  */
@@ -34,5 +38,7 @@ extern char *strptime(const char *, const char *, struct tm *);
 extern char *get_win32_locale_string(int lctype);
 extern char *translate_win32_picture(const char *);
 #endif
-
+#ifdef __cplusplus
+}
+#endif
 #endif

gnucash/gnome/assistant-stock-transaction.cpp

@@ -44,10 +44,13 @@
 
 static QofLogModule log_module = GNC_MOD_ASSISTANT;
 
+extern "C"
+{
 void stock_assistant_prepare (GtkAssistant  *assistant, GtkWidget *page,
                               gpointer user_data);
 void stock_assistant_finish  (GtkAssistant *assistant, gpointer user_data);
 void stock_assistant_cancel  (GtkAssistant *gtkassistant, gpointer user_data);
+}
 
 enum class FieldMask : unsigned;
 bool operator &(FieldMask lhs, FieldMask rhs);