[patch,fortran] Add -fdump-core option to coredump at library run-time errors (PR29649)

[FX Coudert]

> libgfortran/
>
> 2006-11-24  Francois-Xavier Coudert  <coudert@clipper.ens.fr>
>             Tobias Burnus  <burnus@net-b.de>
>
> 	PR fortran/29649
> 	* runtime/environ.c (variable_table): New GFORTRAN_ERROR_DUMPCORE
> 	  environment variable.
> 	* runtime/compile_options.c (set_std): Add new argument.
> 	* runtime/error.c (sys_exit): Move from io/unix.c. Add coredump  
> functionality.
> 	* libgfortran.h (options_t): New dump_core and backtrace members.
> 	  (sys_exit): Move prototype.
> 	* io/unix.c (sys_exit): Move to runtime/error.c.
> 	* configure.ac: Add check for getrlimit.
> 	* configure: Regenerate.
>
>
> fortran/
> 2006-11-24  Francois-Xavier Coudert  <coudert@clipper.ens.fr>
>             Tobias Burnus  <burnus@net-b.de>
>
> 	PR fortran/29649
> 	* gfortran.h (gfc_option_t): Add flag_dump_core.
> 	* lang.opt: Add -fdump-core option.
> 	* invoke.texi: Document the new options.
> 	* trans-decl.c (gfc_build_builtin_function_decls): Add new
> 	  options to the call to set_std.
> 	* options.c (gfc_init_options, gfc_handle_option): Set the
> 	  new options.

I think we've let enough time for people to object the library  
version bump and the plans for converging the ABI. So, your patch is  
OK, Tobias!

Thanks for taking care of this coredump patch,
FX