[vala/0.40] tests: Add invalid "array concatenation" test to increase coverage

[Rico Tzschichholz <ricotz src gnome org>]

commit 00e445244728db4e70434b5944dbbc2198b56d67
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Fri Sep 21 15:14:05 2018 +0200

    tests: Add invalid "array concatenation" test to increase coverage

 tests/Makefile.am                | 1 +
 tests/basic-types/bug570846.test | 8 ++++++++
 2 files changed, 9 insertions(+)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index fabbace3a..aea6c02d7 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -25,6 +25,7 @@ TESTS = \
        basic-types/sizeof.vala \
        basic-types/garray.vala \
        basic-types/glists.vala \
+       basic-types/bug570846.test \
        basic-types/bug571486.vala \
        basic-types/bug591552.vala \
        basic-types/bug595751.vala \
diff --git a/tests/basic-types/bug570846.test b/tests/basic-types/bug570846.test
new file mode 100644
index 000000000..8af1628d5
--- /dev/null
+++ b/tests/basic-types/bug570846.test
@@ -0,0 +1,8 @@
+Invalid Code
+
+void foo (ref string[] bar) {
+       bar += "foo";
+}
+
+void main () {
+}