obstack.h: Merge the following change from gnulib...

include:
	* obstack.h: Merge the following change from gnulib:
	2003-10-21  Paul Eggert  <eggert@twinsun.com>
	* obstack.h (obstack_1grow_fast): Properly parenthesize arg.
	(obstack_ptr_grow_fast, obstack_int_grow_fast):
	Don't use lvalue casts, as GCC plans to remove support for them
	in GCC 3.5.  Reported by Joseph S. Myers.  This bug
	was also present in the non-GCC version, indicating that this
	code had always been buggy and had never been widely used.
	(obstack_1grow, obstack_ptr_grow, obstack_int_grow, obstack_blank):
	Use the fast variant of each macro, rather than copying the
	definiens of the fast variant; that way, we'll be more likely to
	catch future bugs in the fast variants.

gcc:
	* c-typeck.c (pedantic_lvalue_warning): Unconditionally warn of
	deprecation of casts as lvalues.
	* fixinc/inclhack.def (obstack_lvalue_cast): New fix.
	* fixinc/fixincl.x: Regenerate.
	* fixinc/tests/base/obstack.h: New test.

gcc/testsuite:
	* gcc.dg/cast-lvalue-1.c: New test.

From-SVN: r72826