patch 9.1.0637: MS-Windows: Style issues in MSVC Makefile

Problem:  MS-Windows: Style issues in MSVC Makefile
Solution: Fix style issues, simplify logic
          (Ken Takata)

* Add space around the operators for consistency.
* Remove unnecessary ren command. Use the /Fe option to create
  install.exe directly.
* Remove unnecessary mkdir auto command. src/auto should always exist.

closes: #15389

Signed-off-by: Ken Takata <kentkt@csc.jp>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index d526d9f..4d9ba95 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    637,
+/**/
     636,
 /**/
     635,