[RFA:] work around dejagnu bug for simulator targets

[Hans-Peter Nilsson <hans-peter dot nilsson at axis dot com>]

There was a weird discrepancy between cris-elf libstdc++
testsuite runs on Debian systems and Fedora systems, with 59
extra failures on Fedora systems.  After some digging, I found
it was due to a bugfix imported into the debian dejagnu package
but missing in the Fedora package and pristine dejagnu-1.4.4:
<http://lists.gnu.org/archive/html/dejagnu/2004-06/msg00008.html>.
The bug caused input files to be missing, which trigged aborts
in the test-cases, looking like "real" failures.  (Meh, not
really graceful exit behavior there, but once you know the
reason, I guess you just fix it and/or don't care.)

There are signs that there'll be a dejagnu-1.5 release perhaps
this year (just trying to curb your enthusiasm), but I guess
we'll have to support dejagnu-1.4.4 for some time after that.

This patch, the file dejapatches.exp, also tries to establish a
general habitat for current and future gcc-local bugfixes and
overrides (grep for 'delete.*after next [Dd]eja[Gg]nu release'
in gcc/testsuite/lib and you might see a need).  As this is
currently only needed for libstdc++, I didn't touch the other
config/default.exp's.

I tested this against Debian etch, making sure the installed
sim_download was used and on Fedora 8, making sure the fallback
was used.  Both setups now exhibit the same results for
libstdc++-v3.

Incidentally, v3-copy-files should use remote_upload (to
target), not remote_download (from target).  You almost can't
tell the difference, though. :)

Ok to commit?
:ADDPATCH testsuite:

gcc/testsuite:
	* lib/dejapatches.exp: New file.

libstdc++:
	* testsuite/config/default.exp: Load gcc dejapatches.exp.

--- /dev/null	2008-01-22 19:09:36.820000250 +0100
+++ gcc/testsuite/lib/dejapatches.exp	2008-02-05 12:16:40.000000000 +0100
@@ -0,0 +1,35 @@
+#   Copyright (C) 2008 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# Necessary procs and fallbacks for functionality not present in
+# pristine dejagnu-1.4.4.  Make sure overrides here work with updated
+# dejagnu too.
+
+# The absence of sim_download will cause e.g. the libstdc++ testsuite
+# to expose about 59 more FAILs on simulator targets supporting
+# fileio.
+
+if { [info procs sim_download] == "" } {
+    proc sim_download { dest file args } {
+	return [remote_download host $file $args]
+    }
+}
+
+if { [info procs sim_upload] == "" } {
+    proc sim_upload { dest srcfile args } {
+	return [remote_upload host $srcfile $args]
+    }
+}
Index: libstdc++-v3/testsuite/config/default.exp
===================================================================
--- libstdc++-v3/testsuite/config/default.exp	(revision 132071)
+++ libstdc++-v3/testsuite/config/default.exp	(working copy)
@@ -31,3 +31,6 @@
     v3_target_compile $srcfile $destfile $compile_type $options
 }
 
+# Support for old dejagnu.  Must be loaded here, not in libstdc++.exp, to
+# make sure all existing procs are loaded when their presence is tested.
+load_file $srcdir/../../gcc/testsuite/lib/dejapatches.exp