patch 8.1.1076: file for Insert mode is much too big

Problem:    File for Insert mode is much too big.
Solution:   Split off the code for Insert completion. (Yegappan Lakshmanan,
            closes #4044)
diff --git a/Filelist b/Filelist
index 74b9312..7f1afd8 100644
--- a/Filelist
+++ b/Filelist
@@ -48,6 +48,7 @@
 		src/hardcopy.c \
 		src/hashtab.c \
 		src/indent.c \
+		src/insexpand.c \
 		src/json.c \
 		src/json_test.c \
 		src/kword_test.c \
@@ -175,6 +176,7 @@
 		src/proto/hardcopy.pro \
 		src/proto/hashtab.pro \
 		src/proto/indent.pro \
+		src/proto/insexpand.pro \
 		src/proto/json.pro \
 		src/proto/list.pro \
 		src/proto/main.pro \