patch 8.1.2127: the indent.c file is a bit big

Problem:    The indent.c file is a bit big.
Solution:   Move C-indent code a a new cindent.c file.  Move other
            indent-related code to indent.c. (Yegappan Lakshmanan,
            closes #5031)
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index e853ae9..4fb045a 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -719,6 +719,7 @@
 	$(OUTDIR)\bufwrite.obj \
 	$(OUTDIR)\change.obj \
 	$(OUTDIR)\charset.obj \
+	$(OUTDIR)\cindent.obj \
 	$(OUTDIR)\cmdexpand.obj \
 	$(OUTDIR)\cmdhist.obj \
 	$(OUTDIR)\crypt.obj \
@@ -1464,6 +1465,8 @@
 
 $(OUTDIR)/charset.obj:	$(OUTDIR) charset.c  $(INCL)
 
+$(OUTDIR)/cindent.obj:	$(OUTDIR) cindent.c  $(INCL)
+
 $(OUTDIR)/cmdexpand.obj:	$(OUTDIR) cmdexpand.c  $(INCL)
 
 $(OUTDIR)/cmdhist.obj:	$(OUTDIR) cmdhist.c  $(INCL)
@@ -1794,6 +1797,7 @@
 	proto/bufwrite.pro \
 	proto/change.pro \
 	proto/charset.pro \
+	proto/cindent.pro \
 	proto/cmdexpand.pro \
 	proto/cmdhist.pro \
 	proto/crypt.pro \