Failure with PR16566 new test on Mingw hosts

[Alan Modra]

On Tue, May 23, 2023 at 10:48:06AM +0200, Clément Chigot via Binutils wrote:
> I don't know why but this seems to be triggered by the new call to
> bfd_canonicalize_symtab introduced when we are logging the local
> symbols [1].
> Any idea about what's going on ?

The output file is opened "w+b".  ldwrite() will cause some of the
file to be written, but not all is output until bfd_close().  So
reading the symbols means the file IO is write, read, write.  Wild
guess: no fseek or similar between changes in direction?  bfd_seek
doesn't call fseek if the file position doesn't move.

> [1] https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=ld/ldlang.c;hb=HEAD#l4918
> 
> Thanks,
> Clément

-- 
Alan Modra
Australia Development Lab, IBM