libc: Flush buffers before dealing with file positions

libc/src/stdio.cpp

@@ -350,6 +350,8 @@ extern "C"
 
     int fseek(FILE* stream, long offset, int whence)
     {
+        fflush(stream);
+
         long result = lseek(stream->_fd, offset, whence);
         if (result < 0) return -1;
 
@@ -361,11 +363,15 @@ extern "C"
 
     long ftell(FILE* stream)
     {
+        fflush(stream);
+
         return lseek(stream->_fd, 0, SEEK_CUR);
     }
 
     void rewind(FILE* stream)
     {
+        fflush(stream);
+
         lseek(stream->_fd, 0, SEEK_SET);
 
         clearerr(stream);
@@ -383,6 +389,8 @@ extern "C"
 
     int fsetpos(FILE* stream, const fpos_t* pos)
     {
+        fflush(stream);
+
         return fseek(stream, *pos, SEEK_SET);
     }