patch 9.1.0797: testing of options can be further improved

Problem:  testing of options can be further improved
Solution: split the generated option test into test_options_all.vim,
          add more test cases, save and restore values, fix use-after-free

closes: #15894

Signed-off-by: Milly <milly.ca@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index 67ef641..750c194 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -232,6 +232,7 @@
 	test_normal \
 	test_number \
 	test_options \
+	test_options_all \
 	test_packadd \
 	test_partial \
 	test_paste \
@@ -492,6 +493,7 @@
 	test_normal.res \
 	test_number.res \
 	test_options.res \
+	test_options_all.res \
 	test_packadd.res \
 	test_partial.res \
 	test_paste.res \