toolchain: add a program for compiling ipc interface definitions

ifc can be used to compile .if files into self-contained header-only C
libraries, which can be used to send/receive messages that conform
to the described interface.

toolchain/ifc/CMakeLists.txt

@@ -0,0 +1,7 @@
+file(GLOB sources
+	*.c *.h
+	backend/c-mpc/*.c backend/c-mpc/*.h)
+
+add_executable(ifc ${sources})
+
+target_link_libraries(ifc Bluelib::Core Bluelib::Ds Bluelib::Cmd Bluelib::Io)