Add a platform macro indicating whether OS lets temp files be unlinked while open

src/core/file_unix.cpp

@@ -94,7 +94,7 @@ cFile_i::~cFile_i()
         fclose( mpCurrStream );
         mpCurrStream = NULL;
 
-#if IS_AROS || IS_RISCOS
+#if !CAN_UNLINK_WHILE_OPEN // so unlink after close instead
         if( mFlags & cFile::OPEN_LOCKED_TEMP )
         {
             // unlink this file 
@@ -209,7 +209,7 @@ void cFile::Open( const TSTRING& sFileNameC, uint32 flags )
     }
     mpData->m_fd = fh;
 
-#if !IS_AROS && !IS_RISCOS
+#if CAN_UNLINK_WHILE_OPEN
     if( flags & OPEN_LOCKED_TEMP )
     {
         // unlink this file 

src/core/platform.h

@@ -328,6 +328,9 @@
 
 #define SUPPORTS_TERMIOS            (!IS_RTEMS && !IS_REDOX)
 // RTEMS errors are probably just a buildsys issue & this will change or go away.
+// Redox will probably implement this in the future.
+
+#define CAN_UNLINK_WHILE_OPEN       (!IS_AROS && !IS_RISCOS && !IS_REDOX)
 
 #define SUPPORTS_DOUBLE_SLASH_PATH  (IS_CYGWIN)
 // POSIX standard says paths beginning with 2 slashes are "implementation defined"