libstdc++/5697: parallel bootstrap error with gthr.h

[ljrittle@gcc.gnu.org]

Synopsis: parallel bootstrap error with gthr.h

Responsible-Changed-From-To: unassigned->ljrittle
Responsible-Changed-By: ljrittle
Responsible-Changed-When: Fri Feb 15 14:55:05 2002
Responsible-Changed-Why:
    Mine.
State-Changed-From-To: open->analyzed
State-Changed-By: ljrittle
State-Changed-When: Fri Feb 15 14:55:05 2002
State-Changed-Why:
    The proposed fix will not work as the problem is more
    gross than that.  The problem is that thread_builddir
    is independently settable yet mirrors a location known
    to be set.  The correct fix IMHO is to remove
    thread_builddir (map all such uses to target_builddir)
    and add dependancies to the related stamp file (i.e. do
    not depend on directories).

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=5697