test: added funcdefShadowGlobal.st

This tests that a global SNL variable is (correctly) shadowed by a
function parameter with the same name, even in re-entrant mode.

test/compiler/funcdefShadowGlobal.st

+program funcdefShadowGlobalTest
+
+option +r;
+
+int x;
+assign x;
+
+void pvSetX(int x)
+{
+    pvPut(x);
+}
+
+ss simple {
+    state simple {
+        when () {
+            pvSetX(1.0);
+        } exit
+    }
+}

test/compiler/snc_test.plt

@@ -29,6 +29,7 @@ my $error = {
   efGlobal => 3,
   efNoInit => 1,
   efPointer => 1,
+  funcdefShadowGlobal => 1,
   foreignGlobal => 3,
   foreignNoInit => 1,
   misplacedExit => 1,