Import setenv and unsetenv from gnulib

This patch supersedes
https://sourceware.org/ml/gdb-patches/2017-07/msg00009.html

---

Patch [1] broke a build on MinGW hosts, because MinGW doesn't provide POSIX
functions setenv () and unsetenv ().  This can be fixed by using
implementations from gnulib.

[1] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=9a6c7d9c0

gdb/ChangeLog
yyyy-mm-dd  Anton Kolesov  <Anton.Kolesov@synopsys.com>

	* gnulib/update-gnulib.sh (IMPORTED_GNULIB_MODULES): Add setenv and
	unsetenv.
	* gnulib/aclocal.m4: Regenerate.
	* gnulib/config.in: Regenerate.
	* gnulib/configure: Regenerate.
	* gnulib/import/Makefile.am: Regenerate.
	* gnulib/import/Makefile.in: Regenerate.
	* gnulib/import/m4/gnulib-cache.m4: Regenerate.
	* gnulib/import/m4/gnulib-comp.m4: Regenerate.
	* gnulib/import/m4/environ.m4: New file.
	* gnulib/import/m4/setenv.m4: New file.
	* gnulib/import/setenv.c: New file.
	* gnulib/import/unsetenv.c: New file.

1 files changed, 35 insertions, 0 deletions

diff --git a/gdb/gnulib/config.in b/gdb/gnulib/config.in
index 057b12d..6061520 100644
--- a/gdb/gnulib/config.in
+++ b/gdb/gnulib/config.in
@@ -95,6 +95,9 @@
 /* Define to 1 when the gnulib module dirfd should be tested. */
 #undef GNULIB_TEST_DIRFD
 
+/* Define to 1 when the gnulib module environ should be tested. */
+#undef GNULIB_TEST_ENVIRON
+
 /* Define to 1 when the gnulib module frexp should be tested. */
 #undef GNULIB_TEST_FREXP
 
@@ -140,6 +143,9 @@
 /* Define to 1 when the gnulib module rmdir should be tested. */
 #undef GNULIB_TEST_RMDIR
 
+/* Define to 1 when the gnulib module setenv should be tested. */
+#undef GNULIB_TEST_SETENV
+
 /* Define to 1 when the gnulib module stat should be tested. */
 #undef GNULIB_TEST_STAT
 
@@ -152,6 +158,9 @@
 /* Define to 1 when the gnulib module strtok_r should be tested. */
 #undef GNULIB_TEST_STRTOK_R
 
+/* Define to 1 when the gnulib module unsetenv should be tested. */
+#undef GNULIB_TEST_UNSETENV
+
 /* Define to 1 if you have 'alloca' after including <alloca.h>, a header that
    may be supplied by this distribution. */
 #undef HAVE_ALLOCA
@@ -201,6 +210,10 @@
    */
 #undef HAVE_DECL_MEMMEM
 
+/* Define to 1 if you have the declaration of `setenv', and to 0 if you don't.
+   */
+#undef HAVE_DECL_SETENV
+
 /* Define to 1 if you have the declaration of `strtok_r', and to 0 if you
    don't. */
 #undef HAVE_DECL_STRTOK_R
@@ -209,12 +222,19 @@
    don't. */
 #undef HAVE_DECL_TOWLOWER
 
+/* Define to 1 if you have the declaration of `unsetenv', and to 0 if you
+   don't. */
+#undef HAVE_DECL_UNSETENV
+
 /* Define to 1 if you have the <dirent.h> header file. */
 #undef HAVE_DIRENT_H
 
 /* Define to 1 if you have the `dirfd' function. */
 #undef HAVE_DIRFD
 
+/* Define if you have the declaration of environ. */
+#undef HAVE_ENVIRON_DECL
+
 /* Define to 1 if you have the <features.h> header file. */
 #undef HAVE_FEATURES_H
 
@@ -1126,6 +1146,12 @@
 /* Define to 1 if 'long double' and 'double' have the same representation. */
 #undef HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
 
+/* Define to 1 if you have the <search.h> header file. */
+#undef HAVE_SEARCH_H
+
+/* Define to 1 if you have the `setenv' function. */
+#undef HAVE_SETENV
+
 /* Define to 1 if 'sig_atomic_t' is a signed integer type. */
 #undef HAVE_SIGNED_SIG_ATOMIC_T
 
@@ -1189,9 +1215,15 @@
 /* Define to 1 if you have the `towlower' function. */
 #undef HAVE_TOWLOWER
 
+/* Define to 1 if you have the `tsearch' function. */
+#undef HAVE_TSEARCH
+
 /* Define to 1 if you have the <unistd.h> header file. */
 #undef HAVE_UNISTD_H
 
+/* Define to 1 if you have the `unsetenv' function. */
+#undef HAVE_UNSETENV
+
 /* Define to 1 if the system has the type 'unsigned long long int'. */
 #undef HAVE_UNSIGNED_LONG_LONG_INT
 
@@ -1407,6 +1439,9 @@
 #endif
 
 
+/* Define to 1 if unsetenv returns void instead of int. */
+#undef VOID_UNSETENV
+
 /* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
    'wchar_t'. */
 #undef WCHAR_T_SUFFIX