[svn r15] * Fixed a bunch problems with virtual calls. Seems I did some rather poor testing.

* Now 50/51 tests compile.
* Added a simple runalltests.d scripts that should be run with 'gdmd -run runalltests.d' - LLVMDC will not compile it yet.

dmd/mtype.c

@@ -114,7 +114,7 @@ Type::Type(TY ty, Type *next)
     this->arrayof = NULL;
     this->vtinfo = NULL;
     this->ctype = NULL;
-    this->llvmType = 0;
+    this->llvmType = NULL;
 }
 
 Type *Type::syntaxCopy()