patch 9.1.2076: tests: MinGW test fails midway and stops

Problem:  tests: When running the MinGW test, an error occurs after
          generating opt_test.vim.
Solution: Rewrite the error detection in cmd.exe syntax (Muraoka Taro).

The recipe section of src/testdir/Make_ming.mak must be written in
cmd.exe syntax.  This is because "SHELL = cmd.exe" is specified at the
beginning.  However, the error detection in the opt_test.vim recipe is
written in UNXI syntax, which caused the error.

closes: #19146

Signed-off-by: Muraoka Taro <koron.kaoriya@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/testdir/Make_ming.mak

@@ -160,10 +160,7 @@ test_gui_init.res: test_gui_init.vim
 
 opt_test.vim: util/gen_opt_test.vim ../optiondefs.h ../../runtime/doc/options.txt
 	$(VIMPROG) -e -s -u NONE $(COMMON_ARGS) --nofork -S $^
-	@if test -f gen_opt_test.log; then \
-		cat gen_opt_test.log; \
-		exit 1; \
-	fi
+	@if exist gen_opt_test.log ( type gen_opt_test.log & exit /b 1 )
 
 test_bench_regexp.res: test_bench_regexp.vim
 	-$(DEL) benchmark.out

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2076,
 /**/
     2075,
 /**/