patch 7.4.1020

Problem:    On MS-Windows there is no target to run tests with gvim.
Solution:   Add the testgvim target.

Author: brammool

src/Make_mvc.mak

@@ -1027,6 +1027,11 @@ test:
 	$(MAKE) /NOLOGO -f Make_dos.mak win32
 	cd ..
 
+testgvim:
+	cd testdir
+	$(MAKE) /NOLOGO -f Make_dos.mak VIMPROG=..\gvim win32
+	cd ..
+
 testclean:
 	cd testdir
 	$(MAKE) /NOLOGO -f Make_dos.mak clean

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1020,
 /**/
     1019,
 /**/