SDL_config.h: Define HAVE_STRLCPY on some platforms.

This makes 1.2 apps compiled with sdl12-compat's headers work with
a real SDL 1.2 library on macOS. Otherwise: missing symbol.

Author: icculus

include/SDL/SDL_config.h

@@ -133,7 +133,6 @@ stage, though. Send patches if your platform lacks something. */
 #define HAVE_BCOPY 1
 #define HAVE_ATOI 1
 #define HAVE_ATOF 1
-#define HAVE_STRLCPY 1
 #define HAVE_STRLCAT 1
 #define HAVE__STRREV 1
 #define HAVE__STRUPR 1
@@ -166,6 +165,10 @@ stage, though. Send patches if your platform lacks something. */
 #define HAVE_SETJMP 1
 #endif
 
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__OpenBSD__)  /* macos and BSDs have this. */
+#define HAVE_STRLCPY 1
+#endif
+
 /* Don't define most of the SDL backends, under the assumption checking for these against the headers won't work anyhow.
    The exception is the X11 backend; you need its define to know if you can use its syswm interface. */