Nuke COMPILE_FOR_R5.

Not used in $long_time, almost certainly broken, so it's just cruft.

headers/build/os/drivers/Select.h

@@ -1,5 +1,5 @@
 /* File System and Drivers select support
-** 
+**
 ** Distributed under the terms of the Haiku License.
 */
 #ifndef _DRIVERS_SELECT_H
@@ -31,11 +31,7 @@ enum select_events {
 extern "C" {
 #endif
 
-#ifdef COMPILE_FOR_R5
-extern void notify_select_event(struct selectsync *sync, uint32 ref);
-#else
 extern status_t notify_select_event(struct selectsync *sync, uint32 ref, uint8 event);
-#endif
 
 #ifdef __cplusplus
 }

headers/os/interface/InterfaceDefs.h

@@ -27,11 +27,9 @@ class BRect;
 #define B_UTF8_TRADEMARK	"\xE2\x84\xA2"
 #define B_UTF8_SMILING_FACE	"\xE2\x98\xBB"
 #define B_UTF8_HIROSHI		"\xE5\xBC\x98"
-#ifdef COMPILE_FOR_R5
-	#define B_MAX_MOUSE_BUTTONS 3
-#else
-	#define B_MAX_MOUSE_BUTTONS 16
-#endif
+
+
+#define B_MAX_MOUSE_BUTTONS 16
 
 
 // Key definitions