allow preferring linking against dynamic libgcc over static one

[Jan Beulich]

This is puzzling. In the very same place there is use of
USE_LD_AS_NEEDED, introduced in April. Why would the rules you try to
enforce here not hold for that one (it's neither documented nor being
checked for at runtime)? Jan

>>> "Joseph S. Myers" <jsm@polyomino.org.uk> 07.07.04 13:57:30 >>>
On Wed, 7 Jul 2004, Jan Beulich wrote:

> 2004-07-07 Jan Beulich <jbeulich@novell.com>
> 
> 	* gcc.c (init_gcc_specs): Conditionalize upon
> PREFER_SHARED_LIBGCC.

Apart from needing documentation for any new target macros and hooks,
it's
better to check such macros - if you use a macro rather than a hook -
with
if (PREFER_SHARED_LIBGCC) (and to have a default definition in
defaults.h)
rather than #ifdef/#ifndef (if the macro is constant, the other side
will
get optimized out, but will still get checked for syntax so be a bit
less
likely to bitrot).

-- 
Joseph S. Myers               http://www.srcf.ucam.org/~jsm28/gcc/ 
    jsm@polyomino.org.uk (personal mail)
    jsm28@gcc.gnu.org (Bugzilla assignments and CCs)