// allocate a new arena.
	lock(&gcBitsArenas.lock)
	// Try the head arena again, since it may have changed. Now
	// that we hold the lock, the list head can't change, but its
	// free position still can.
	if p := gcBitsArenas.next.tryAlloc(bytesNeeded); p != nil {
		unlock(&gcBitsArenas.lock)
		return p
	}

	// Allocate a new arena. This may temporarily drop the lock.

	for _, p := range ldflag {
		argv = append(argv, p)
		checkStatic(p)
	}

	// When building a program with the default -buildmode=exe the
	// gc compiler generates code requires DT_TEXTREL in a
	// position independent executable (PIE). On systems where the
	// toolchain creates PIEs by default, and where DT_TEXTREL
	// does not work, the resulting programs will not run. See

	off int
}

// Error implements the builtin error interface for demangleErr.
func (de demangleErr) Error() string {
	return fmt.Sprintf("%s at %d", de.err, de.off)
}

// adjustErr adjusts the position of err, if it is a demangleErr,
// and returns err.
func adjustErr(err error, adj int) error {
	if err == nil {
		return nil
	}
	if de, ok := err.(demangleErr); ok {
		de.off += adj
		return de
	}