patch 8.1.1727: code for viminfo support is spread out

Problem:    Code for viminfo support is spread out.
Solution:   Move to code to viminfo.c. (Yegappan Lakshmanan, closes #4686)
diff --git a/src/Make_cyg_ming.mak b/src/Make_cyg_ming.mak
index a54730b..4ceaa91 100644
--- a/src/Make_cyg_ming.mak
+++ b/src/Make_cyg_ming.mak
@@ -772,6 +772,7 @@
 	$(OUTDIR)/usercmd.o \
 	$(OUTDIR)/userfunc.o \
 	$(OUTDIR)/version.o \
+	$(OUTDIR)/viminfo.o \
 	$(OUTDIR)/winclip.o \
 	$(OUTDIR)/window.o