[libc] Created syscall trampolines in libc

Using syscalls.inc (moved to src/include) generate trampoline functions
for directly calling syscalls with libc functions.

src/include/syscalls.inc

@@ -0,0 +1,19 @@
+SYSCALL(0x00, system_log,       const char *)
+SYSCALL(0x01, system_noop,      void)
+
+SYSCALL(0x09, object_wait,      j6_handle_t, j6_signal_t, j6_signal_t *)
+SYSCALL(0x0a, object_signal,    j6_handle_t, j6_signal_t)
+
+SYSCALL(0x10, process_koid,     j6_koid_t *)
+SYSCALL(0x11, process_exit,     int64_t)
+
+SYSCALL(0x18, thread_koid,      j6_koid_t *)
+SYSCALL(0x19, thread_create,    void *, j6_handle_t *)
+SYSCALL(0x1a, thread_exit,      int64_t)
+SYSCALL(0x1b, thread_pause,     void)
+SYSCALL(0x1c, thread_sleep,     uint64_t)
+
+SYSCALL(0x20, channel_create,   j6_handle_t *)
+SYSCALL(0x21, channel_close,    j6_handle_t)
+SYSCALL(0x22, channel_send,     j6_handle_t, size_t, void *)
+SYSCALL(0x23, channel_receive,  j6_handle_t, size_t *, void *)