patch 9.1.0760: tests: no error reported, if gen_opt_test.vim fails

Problem:  tests: no error reported, if gen_opt_test.vim fails
Solution: Make Vim exit with return code 1 in case of any error
          (Milly)

closes: #15795

Signed-off-by: Milly <milly.ca@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/Make_ming.mak b/src/testdir/Make_ming.mak
index 2676111..f26950e 100644
--- a/src/testdir/Make_ming.mak
+++ b/src/testdir/Make_ming.mak
@@ -158,7 +158,7 @@
 	@$(DEL) vimcmd
 
 opt_test.vim: ../optiondefs.h gen_opt_test.vim
-	$(VIMPROG) -u NONE -S gen_opt_test.vim --noplugin --not-a-term ../optiondefs.h
+	$(VIMPROG) -e -s -u NONE $(COMMON_ARGS) --nofork -S gen_opt_test.vim ../optiondefs.h
 
 test_bench_regexp.res: test_bench_regexp.vim
 	-$(DEL) benchmark.out
diff --git a/src/testdir/Make_mvc.mak b/src/testdir/Make_mvc.mak
index 1bf9eae..bb38e25 100644
--- a/src/testdir/Make_mvc.mak
+++ b/src/testdir/Make_mvc.mak
@@ -152,7 +152,7 @@
 	@del vimcmd
 
 opt_test.vim: ../optiondefs.h gen_opt_test.vim
-	$(VIMPROG) -u NONE -S gen_opt_test.vim --noplugin --not-a-term ../optiondefs.h
+	$(VIMPROG) -e -s -u NONE $(COMMON_ARGS) --nofork -S gen_opt_test.vim ../optiondefs.h
 
 test_bench_regexp.res: test_bench_regexp.vim
 	-if exist benchmark.out del benchmark.out
diff --git a/src/testdir/Makefile b/src/testdir/Makefile
index b6e8c80..2827f99 100644
--- a/src/testdir/Makefile
+++ b/src/testdir/Makefile
@@ -161,7 +161,7 @@
 	@rm vimcmd
 
 opt_test.vim: ../optiondefs.h gen_opt_test.vim
-	$(VIMPROG) -u NONE -S gen_opt_test.vim --noplugin --not-a-term ../optiondefs.h
+	$(VIMPROG) -e -s -u NONE $(NO_INITS) --nofork --gui-dialog-file guidialog -S gen_opt_test.vim ../optiondefs.h
 
 test_xxd.res:
 	XXD=$(XXDPROG); export XXD; $(RUN_VIMTEST) $(NO_INITS) -S runtest.vim test_xxd.vim
diff --git a/src/testdir/gen_opt_test.vim b/src/testdir/gen_opt_test.vim
index 5be06ce..09db320 100644
--- a/src/testdir/gen_opt_test.vim
+++ b/src/testdir/gen_opt_test.vim
@@ -1,10 +1,12 @@
-" Script to generate testdir/opt_test.vim from option.c
+" Script to generate testdir/opt_test.vim from optiondefs.h
 
 set cpo=&vim
 
 " Only do this when build with the +eval feature.
 if 1
 
+try
+
 set nomore
 
 const K_KENTER = -16715
@@ -244,6 +246,13 @@
 
 call writefile(script, 'opt_test.vim')
 
+" Exit with error-code if error occurs.
+catch
+  set verbose=1
+  echoc 'Error:' v:exception 'in' v:throwpoint
+  cq! 1
+endtry
+
 endif
 
 qa!
diff --git a/src/version.c b/src/version.c
index 63a6bc0..eff0cf8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    760,
+/**/
     759,
 /**/
     758,