sdl12-compat: Add log output at startup.

From 172221732ac6c52cc3b417e00b034c59dd5d8fa2 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Tue, 27 Apr 2021 15:34:34 -0400
Subject: [PATCH] Add log output at startup.

This makes it clear this is sdl12-compat running, instead of SDL 1.2 classic.
And, for my testing and iteration purposes, tells me I'm running the right
build of it.  :)
---
 src/SDL12_compat.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/SDL12_compat.c b/src/SDL12_compat.c
index d39e9bd..d5f055b 100644
--- a/src/SDL12_compat.c
+++ b/src/SDL12_compat.c
@@ -940,6 +940,12 @@ LoadSDL20(void)
                 okay = (SDL_VERSIONNUM(v.major,v.minor,v.patch) >= SDL20_REQUIRED_VER);
                 if (!okay) {
                     sprintf_fn(loaderror, "SDL2 %d.%d.%d library is too old.", v.major, v.minor, v.patch);
+                } else {
+                    #if defined(__DATE__) && defined(__TIME__)
+                    SDL20_Log("sdl12-compat, built on " __DATE__ " at " __TIME__ ", talking to SDL2 %d.%d.%d", v.major, v.minor, v.patch);
+                    #else
+                    SDL20_Log("sdl12-compat, talking to SDL2 %d.%d.%d", v.major, v.minor, v.patch);
+                    #endif
                 }
             }
             if (!okay) {