Import posix_spawn from Gnulib.

posix_spawn is less error-prone than vfork + exec, and can make use of
system-specific optimizations like `clone' on Linux.  Import Gnulib
replacement so that we can use recent additions like
`posix_spawn_file_actions_addchdir'.

The only manual change are to admin/merge-gnulib and .gitignore.  All
other changes are due to rerunning merge-gnulib.

* admin/merge-gnulib (GNULIB_MODULES): Add posix_spawn-related
modules.
* .gitignore: Add new generated files.

1 files changed, 28 insertions, 0 deletions

diff --git a/lib/strchrnul.valgrind b/lib/strchrnul.valgrind
new file mode 100644
index 00000000000..a85608a7c76
--- /dev/null
+++ b/lib/strchrnul.valgrind
@@ -0,0 +1,28 @@
+# Suppress a valgrind message about use of uninitialized memory in strchrnul().
+
+# Copyright (C) 2008-2020 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+
+# This use is OK because it provides only a speedup.
+{
+    strchrnul-value4
+    Memcheck:Value4
+    fun:strchrnul
+}
+{
+    strchrnul-value8
+    Memcheck:Value8
+    fun:strchrnul
+}