Don't print the entire declaration of the alliassee when `->toChars()` is called on an `AliasDeclaration`; just printing the name will do. This fixes #305, which otherwise tries to generate {{{ class E { void A() { alias /* recurse into E->toCBuffer() */ m; } } }}} by way of an infinite recursion (causing a segfault when the stack runs out).

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/mini/compile_bug305.d	Wed May 20 16:20:59 2009 +0200
@@ -0,0 +1,7 @@
+module bug305;
+
+class E {
+    void A() {
+        alias E m;
+    }
+}