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_cyg_ming.mak b/src/Make_cyg_ming.mak
index eb6d696..6a3cf81 100644
--- a/src/Make_cyg_ming.mak
+++ b/src/Make_cyg_ming.mak
@@ -711,6 +711,7 @@
 	$(OUTDIR)/buffer.o \
 	$(OUTDIR)/change.o \
 	$(OUTDIR)/charset.o \
+	$(OUTDIR)/cmdexpand.o \
 	$(OUTDIR)/cmdhist.o \
 	$(OUTDIR)/crypt.o \
 	$(OUTDIR)/crypt_zip.o \