[gnome-chess] Remove broken attempt to set PR_SET_PDEATHSIG in subprocess

[Michael Catanzaro <mcatanzaro src gnome org>]

commit c60c4380df5a756ff683500ad5349d353410d2e9
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Sun Jan 27 15:00:29 2019 -0600

    Remove broken attempt to set PR_SET_PDEATHSIG in subprocess
    
    This has been broken for a long time, and I can't figure out how to fix
    it.
    
    If we bring it back, it should be done directly in Vala now, rather than
    C, since we no longer distribute C sources. See
    bdd5ff69fe04d41e28c44c523facc5e3f48ac47a for the commit that originally
    translated this from Vala to C.

 meson.build           |  2 --
 src/chess-engine.vala |  3 +--
 src/meson.build       |  4 ----
 src/portability.c     | 30 ------------------------------
 src/portability.h     | 17 -----------------
 src/portability.vapi  |  5 -----
 6 files changed, 1 insertion(+), 60 deletions(-)
---
diff --git a/meson.build b/meson.build
index ba6419a..83f6786 100644
--- a/meson.build
+++ b/meson.build
@@ -35,11 +35,9 @@ gtk = dependency('gtk+-3.0', version: '>= 3.20.0')
 librsvg = dependency('librsvg-2.0', version: '>= 2.32.0')
 
 posix = meson.get_compiler('vala').find_library('posix')
-has_prctl = meson.get_compiler('c').has_header('sys/prctl.h')
 
 # Configuration
 conf = configuration_data()
-conf.set10('HAVE_LINUX_PRCTL_H', has_prctl)
 conf.set_quoted('GETTEXT_PACKAGE', meson.project_name())
 conf.set_quoted('LOCALEDIR', localedir)
 conf.set_quoted('PACKAGE_NAME', meson.project_name())
diff --git a/src/chess-engine.vala b/src/chess-engine.vala
index 5cf0587..fbf630c 100644
--- a/src/chess-engine.vala
+++ b/src/chess-engine.vala
@@ -80,8 +80,7 @@ public abstract class ChessEngine : Object
         {
             Process.spawn_async_with_pipes (null, argv, null,
                                             SpawnFlags.SEARCH_PATH | SpawnFlags.DO_NOT_REAP_CHILD,
-                                            () => Portability.maybe_kill_orphan_engine (),
-                                            out pid, out stdin_fd, out stdout_fd, out stderr_fd);
+                                            null, out pid, out stdin_fd, out stdout_fd, out stderr_fd);
         }
         catch (SpawnError e)
         {
diff --git a/src/meson.build b/src/meson.build
index 98704b4..5052848 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -8,10 +8,6 @@ resources = gnome.compile_resources(application_id, resource_files,
 # The gnome-chess binary
 chess_sources = [
   resources,
-
-  'portability.c',
-  'portability.vapi',
-
   'ai-profile.vala',
   'chess-engine-cecp.vala',
   'chess-engine-uci.vala',