[Patch, fortran] PR37011 - F2003, type extension: multiple inheritence not rejected

[Paul Richard Thomas]

Committed as obvious after bootstrapping and regtesting on x86_ia64/FC8

'extension' is now in line with other attributes in the way in which
it is applied.

Paul

2008-08-09  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/37011
	* symbol.c (gfc_add_extension): New function.
	* decl.c (gfc_get_type_attr_spec): Call it.
	(gfc_match_derived_decl): Set symbol extension attribute from
	attr.extension.
	* gfortran.h : Add prototype for gfc_add_extension.