Fix #163.

tests/mini/bug163_void_condexp.d

@@ -0,0 +1,18 @@
+
+static foocalled = false;
+static barcalled = false;
+void foo() { foocalled = true; }
+void bar() { barcalled = true; }
+
+void f(bool b)
+{
+  return b ? foo() : bar();
+}
+
+void main()
+{
+  f(true);
+  assert(foocalled && !barcalled);
+  f(false);
+  assert(foocalled && barcalled);
+}