patch 8.2.0527: Vim9: function types insufficiently tested

Problem:    Vim9: function types insufficiently tested.
Solution:   Add more tests.  Fix white space check.  Add "test_vim9" target.
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index 8ca7831..63d97e8 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -43,6 +43,19 @@
 # Tests for the GUI.
 SCRIPTS_GUI =
 
+# Tests for Vim9 script.
+TEST_VIM9 = \
+	test_vim9_disassemble \
+	test_vim9_expr \
+	test_vim9_func \
+	test_vim9_script
+
+TEST_VIM9_RES = \
+	test_vim9_disassemble.res \
+	test_vim9_expr.res \
+	test_vim9_func.res \
+	test_vim9_script.res
+
 # Individual tests, including the ones part of test_alot.
 # Please keep sorted up to test_alot.
 NEW_TESTS = \
@@ -272,10 +285,7 @@
 	test_utf8 \
 	test_utf8_comparisons \
 	test_vartabs \
-	test_vim9_disassemble \
-	test_vim9_expr \
-	test_vim9_func \
-	test_vim9_script \
+	$(TEST_VIM9) \
 	test_viminfo \
 	test_vimscript \
 	test_virtualedit \
@@ -482,10 +492,7 @@
 	test_user_func.res \
 	test_usercommands.res \
 	test_vartabs.res \
-	test_vim9_disassemble.res \
-	test_vim9_expr.res \
-	test_vim9_func.res \
-	test_vim9_script.res \
+	$(TEST_VIM9_RES) \
 	test_viminfo.res \
 	test_vimscript.res \
 	test_virtualedit.res \