patch 8.1.1886: command line expansion code is spread out

Problem:    Command line expansion code is spread out.
Solution:   Move the code to cmdexpand.c. (Yegappan Lakshmanan, closes #4831)
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index 56dabe9..301087d 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -720,6 +720,7 @@
 	$(OUTDIR)\buffer.obj \
 	$(OUTDIR)\change.obj \
 	$(OUTDIR)\charset.obj \
+	$(OUTDIR)\cmdexpand.obj \
 	$(OUTDIR)\cmdhist.obj \
 	$(OUTDIR)\crypt.obj \
 	$(OUTDIR)\crypt_zip.obj \
@@ -1450,6 +1451,8 @@
 
 $(OUTDIR)/charset.obj:	$(OUTDIR) charset.c  $(INCL)
 
+$(OUTDIR)/cmdexpand.obj:	$(OUTDIR) cmdexpand.c  $(INCL)
+
 $(OUTDIR)/cmdhist.obj:	$(OUTDIR) cmdhist.c  $(INCL)
 
 $(OUTDIR)/crypt.obj:	$(OUTDIR) crypt.c  $(INCL)
@@ -1754,6 +1757,7 @@
 	proto/buffer.pro \
 	proto/change.pro \
 	proto/charset.pro \
+	proto/cmdexpand.pro \
 	proto/cmdhist.pro \
 	proto/crypt.pro \
 	proto/crypt_zip.pro \