Add defines for byond-tracy support (#70931)

Adds `USE_BYOND_TRACY`, which automatically loads a given
prof.dll/libprof.so using https://github.com/mafemergency/byond-tracy/.

Not intended for use in production, and we do not ship a copy of
byond-tracy. It is extremely easy to compile yourself, but if you're
someone interesting enough to play around with this then let me know and
I can just give you a build.

I'm going to be using this for init profiling.

code/game/world.dm

@@ -14,6 +14,11 @@ GLOBAL_LIST(topic_status_cache)
 		LIBCALL(dll, "auxtools_init")()
 		enable_debugging()
 
+#ifdef USE_BYOND_TRACY
+	#warn USE_BYOND_TRACY is enabled
+	init_byond_tracy()
+#endif
+
 	world.Profile(PROFILE_START)
 	log_world("World loaded at [TIME_STAMP("hh:mm:ss", FALSE)]!")
 
@@ -369,3 +374,19 @@ GLOBAL_LIST(topic_status_cache)
 
 /world/proc/on_tickrate_change()
 	SStimer?.reset_buckets()
+
+/world/proc/init_byond_tracy()
+	var/library
+
+	switch (system_type)
+		if (MS_WINDOWS)
+			library = "prof.dll"
+		if (UNIX)
+			library = "libprof.so"
+		else
+			CRASH("Unsupported platform: [system_type]")
+
+	var/init_result = call(library, "init")()
+	if (init_result != "0")
+		CRASH("Error initializing byond-tracy: [init_result]")
+