IPCCompiler: Start working on a simple IPC definition language

Instead of doing everything manually in C++, let's do some codegen.
This patch adds a crude but effective IPC definition parser, along
with two initial definition files for the AudioServer's client and
server endpoints.

Servers/AudioServer/AudioClient.ipc

@@ -0,0 +1,4 @@
+endpoint AudioClient
+{
+    FinishedPlayingBuffer(i32 buffer_id) =|
+}

Servers/AudioServer/AudioServer.ipc

@@ -0,0 +1,9 @@
+endpoint AudioServer
+{
+    Greet(i32 client_pid) => (i32 server_pid, i32 client_id)
+
+    GetMainMixVolume() => (i32 volume)
+    SetMainMixVolume(i32 volume) => ()
+
+    EnqueueBuffer(i32 buffer_id) => ()
+}