[vala] add missing test from previous commit

[Luca Bruno <lucabru src gnome org>]

commit dc94a6e2747da7aae38923f0deeea6765fc315f1
Author: Luca Bruno <lucabru src gnome org>
Date:   Sun Jun 21 15:41:48 2015 +0200

    add missing test from previous commit

 tests/basic-types/bug643612.vala |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/tests/basic-types/bug643612.vala b/tests/basic-types/bug643612.vala
new file mode 100644
index 0000000..470e1f1
--- /dev/null
+++ b/tests/basic-types/bug643612.vala
@@ -0,0 +1,4 @@
+void main() {
+       int8 test1 = -128;
+       int8 test2 = +127;
+}
\ No newline at end of file