patch 8.1.1318: code for text changes is in a "misc" file

Problem:    Code for text changes is in a "misc" file.
Solution:   Move the code to change.c.
diff --git a/src/Make_manx.mak b/src/Make_manx.mak
index e53522f..211d8cc 100644
--- a/src/Make_manx.mak
+++ b/src/Make_manx.mak
@@ -40,6 +40,7 @@
 	autocmd.c \
 	blowfish.c \
 	buffer.c \
+	change.c \
 	charset.c \
 	crypt.c \
 	crypt_zip.c \
@@ -104,6 +105,7 @@
 	obj/autocmd.o \
 	obj/blowfish.o \
 	obj/buffer.o \
+	obj/change.o \
 	obj/charset.o \
 	obj/crypt.o \
 	obj/crypt_zip.o \
@@ -166,6 +168,7 @@
 	proto/autocmd.pro \
 	proto/blowfish.pro \
 	proto/buffer.pro \
+	proto/change.pro \
 	proto/charset.pro \
 	proto/crypt.pro \
 	proto/crypt_zip.pro \
@@ -280,6 +283,9 @@
 obj/buffer.o:	buffer.c
 	$(CCSYM) $@ buffer.c
 
+obj/change.o:	change.c
+	$(CCSYM) $@ change.c
+
 obj/charset.o:	charset.c
 	$(CCSYM) $@ charset.c