GDB server: fix tests following recent commits.
Fixes #276987.  (Philippe Waroquiers, philippe.waroquiers@skynet.be)

* make_local_links
  - disable gdb tests if gdb version < 7
  - disable pic tests if gdb version < 7.1
* nlfork_chain test
  - reduce chain from 20 to 15 to avoid ENOMEM
    on small ARM systems
* main_pic.c
  - put break at line 11 rather than main entry, as ARM gdb
     does not properly show main args till it has started executing.
* passsigalrm.c
  - do not setsa.sa_restorer (obsolete on linux, unknown on darwin)
* mcvabits.vgtest
  - make prereq consistent with other tests
* filter_gdb
  - upgraded filter to new linenr in clean_after_fork.c



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11853 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/gdbserver_tests/fork_chain.c b/gdbserver_tests/fork_chain.c
index ae40f6e..b5d60f0 100644
--- a/gdbserver_tests/fork_chain.c
+++ b/gdbserver_tests/fork_chain.c
@@ -32,6 +32,6 @@
 }
 int main()
 {
-   fork_chain (20);
+   fork_chain (15);
    return 0;
 }