patch 8.2.1269: language and locale code spread out

Problem:    Language and locale code spread out.
Solution:   Move relevant code to src/locale.c. (Yegappan Lakshmanan,
            closes #6509)
diff --git a/Filelist b/Filelist
index 77fabbe..1e22554 100644
--- a/Filelist
+++ b/Filelist
@@ -76,6 +76,7 @@
 		src/json_test.c \
 		src/kword_test.c \
 		src/list.c \
+		src/locale.c \
 		src/keymap.h \
 		src/macros.h \
 		src/main.c \
@@ -247,6 +248,7 @@
 		src/proto/insexpand.pro \
 		src/proto/json.pro \
 		src/proto/list.pro \
+		src/proto/locale.pro \
 		src/proto/main.pro \
 		src/proto/map.pro \
 		src/proto/mark.pro \