Improvements for testing and compilation breakage for the GDB server
on various platforms:

* In all gdbserver_tests using gdb:
  Made a more general way to remove the initial start message.

* tests using threads burning cpu modified to have only 1 thread.
  This makes them independent of the scheduler fairness.

* filter_gdb and filter_vgdb enhanced to anonymise
    some debian 6.0/ppc specific things
    some s390x/gdb 7.0, gdb 7.1  specific things

* vgdb.c: added an #include <linux/ptrace.h> to fix compilation
  on s390x fedora and suse. (Christian Boerntrager)

* fixed a bug in valgrind-low.c debug log :
  when a register size is 0, its image cannot be output (and register
  should not be transferred).

* added a parameter --keep-unfiltered to vg_regtest.in
  This will make it easier to update filter_gdb:
  in case gdbserver_tests are failing due to "artificial"
  differences to be filtered, re-run the tests using:
     perl tests/vg_regtest --keep-unfiltered gdbserver_tests
  Then a tar file with all the *.out in gdbserver_tests
  will allow me to better/faster update the filter_gdb.

* made a better detection of a working PTRACE_GETREGS at compile time
  and/or at run-time.

This is the patch on bug 214909 comment 69.
(Philippe Waroquiers, philippe.waroquiers@skynet.be)



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11740 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/gdbserver_tests/mssnapshot.stdinB.gdb b/gdbserver_tests/mssnapshot.stdinB.gdb
index 42b56fe..efe5a7e 100644
--- a/gdbserver_tests/mssnapshot.stdinB.gdb
+++ b/gdbserver_tests/mssnapshot.stdinB.gdb
@@ -1,5 +1,6 @@
 # connect gdb to Valgrind gdbserver:
 target remote | ./vgdb --wait=60 --vgdb-prefix=./vgdb-prefix-mssnapshot
+echo vgdb launched process attached\n
 monitor vg.set vgdb-error 999999
 #
 #