Define various symbols conditionally in shared libraries executables

[Hans-Peter Nilsson]

> Date: Tue, 12 Jun 2018 23:44:26 +0930
> From: Alan Modra <amodra@gmail.com>

> On Tue, Jun 12, 2018 at 05:37:03AM +0200, Hans-Peter Nilsson wrote:
> I test cris-elf, which needed a change, and crisv32-linux.  On looking
> at my logs I see the libdso-1 test wasn't run for the linux target..
> In fact, none of the ld-cris/ tests were run, for a fairly obvious
> reason.

Hah, ![istarget cris-*-*].  Though, I believe there'd be too
many bit-patterns to tweak, so that has to stay.

> The cris-elf dump looks like:
> 
> ld/tmpdir/libdso-1.so:     file format elf32-cris

Hm, this test runs for cris-elf?  DSOs don't make much sense
there...'k, apparently I set all required options to generate a
DSO, but apparently there's still a size difference.  The
purpose is to have cris-elf be the catch-all target.

> DYNAMIC SYMBOL TABLE:
> 000000d0 g    DF .text	00000002 dsofn
> 
> So it would seem the patch should have made the address match
> 00000[01].[02468ace]

Right, though (IIRC) the purpose of the address pattern not
being ".+" is that I want to exclude 0 (and the last part is
that functions start on an even address).  Though, that doesn't
seem important enough to worry about.

Ok, thanks for clarifying; I'll fix.

brgds, H-P