PCH support on Solaris

[Geoff Keating]

> From: Eric Botcazou <ebotcazou@libertysurf.fr>
> Date: Wed, 2 Apr 2003 19:39:48 +0200

> In other words, Solaris appears to map the whole file, whatever offset you 
> specify in the call to mmap, so that the address returned is
> 
> 	addr = mmi.preferred_base + mmi.offset
> 
> 
> The reporter of PR other/9830 proposes to force the address by passing 
> MAP_FIXED to mmap; this works (all pch tests of the testsuite pass) but, if 
> my interpretation is correct, this could fail if the pages before the forced 
> address are for some reason unmappable.

I think we discussed this more in the PR and the suggestion was to use
MAP_FIXED but to check that the area was safe to map into.  There's
sample code in the PR, I think, but it really needs someone with a
Solaris machine to do a proper patch using host-hooks.

-- 
- Geoffrey Keating <geoffk@geoffk.org>