patch 8.2.0847: typval related code is spread out

Problem:    Typval related code is spread out.
Solution:   Move code to new typval.c file. (Yegappan Lakshmanan, closes #6093)
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index 8240f50..aec94a9 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -811,6 +811,7 @@
 	$(OUTDIR)\textobject.obj \
 	$(OUTDIR)\textprop.obj \
 	$(OUTDIR)\time.obj \
+	$(OUTDIR)\typval.obj \
 	$(OUTDIR)\ui.obj \
 	$(OUTDIR)\undo.obj \
 	$(OUTDIR)\usercmd.obj \
@@ -1755,6 +1756,8 @@
 
 $(OUTDIR)/time.obj:	$(OUTDIR) time.c  $(INCL)
 
+$(OUTDIR)/typval.obj:	$(OUTDIR) typval.c  $(INCL)
+
 $(OUTDIR)/ui.obj:	$(OUTDIR) ui.c  $(INCL)
 
 $(OUTDIR)/undo.obj:	$(OUTDIR) undo.c  $(INCL)
@@ -1954,6 +1957,7 @@
 	proto/textobject.pro \
 	proto/textprop.pro \
 	proto/time.pro \
+	proto/typval.pro \
 	proto/ui.pro \
 	proto/undo.pro \
 	proto/usercmd.pro \