IPCCompiler: Use string hashes for IPC endpoint magic

This patch removes the IPC endpoint numbers that needed to be specified
in the IPC files.  Since the string hash is a (hopefully) collision free
number that depends on the name of the endpoint, we now use that
instead. :^)

Userland/Services/LookupServer/LookupClient.ipc

@@ -1,4 +1,4 @@
-endpoint LookupClient = 9002
+endpoint LookupClient
 {
     Dummy() =|
 }

Userland/Services/LookupServer/LookupServer.ipc

@@ -1,4 +1,4 @@
-endpoint LookupServer = 9001
+endpoint LookupServer
 {
     LookupName(String name) => (int code, Vector<String> addresses)
     LookupAddress(String address) => (int code, String name)