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_vms.mms b/src/Make_vms.mms
index 6046b5a..3decf69 100644
--- a/src/Make_vms.mms
+++ b/src/Make_vms.mms
@@ -318,6 +318,7 @@
 	bufwrite.c \
 	change.c \
 	charset.c \
+	cindent.c \
 	cmdexpand.c \
 	cmdhist.c \
 	crypt.c \
@@ -420,6 +421,7 @@
 	bufwrite.obj \
 	change.obj \
 	charset.obj \
+	cindent.obj \
 	cmdexpand.obj \
 	cmdhist.obj \
 	crypt.obj \
@@ -700,6 +702,10 @@
  ascii.h keymap.h term.h macros.h structs.h regexp.h \
  gui.h beval.h [.proto]gui_beval.pro option.h ex_cmds.h proto.h \
  globals.h
+cindent.obj : cindent.c vim.h [.auto]config.h feature.h os_unix.h \
+ ascii.h keymap.h term.h macros.h structs.h regexp.h \
+ gui.h beval.h [.proto]gui_beval.pro option.h ex_cmds.h proto.h \
+ globals.h
 cmdexpand.obj : cmdexpand.c vim.h [.auto]config.h feature.h os_unix.h \
  ascii.h keymap.h term.h macros.h structs.h regexp.h \
  gui.h beval.h [.proto]gui_beval.pro option.h ex_cmds.h proto.h \