libstdc++: Default to --enable-libstdcxx-filesystem-ts for *-*-mingw*

	* acinclude.m4 (GLIBCXX_ENABLE_FILESYSTEM_TS): Enable by default for
	mingw targets.
	* configure: Regenerate.

From-SVN: r278870

libstdc++-v3/ChangeLog

 2019-11-30  Jonathan Wakely  <jwakely@redhat.com>
 
+	* acinclude.m4 (GLIBCXX_ENABLE_FILESYSTEM_TS): Enable by default for
+	mingw targets.
+	* configure: Regenerate.
+
 	* include/bits/fs_path.h (u8path(InputIterator, InputIterator))
 	(u8path(const Source&)) [_GLIBCXX_FILESYSTEM_IS_WINDOWS]: Simplify
 	conditions.

libstdc++-v3/acinclude.m4

@@ -4436,6 +4436,9 @@ AC_DEFUN([GLIBCXX_ENABLE_FILESYSTEM_TS], [
       solaris*)
         enable_libstdcxx_filesystem_ts=yes
         ;;
+      mingw*)
+        enable_libstdcxx_filesystem_ts=yes
+        ;;
       *)
         enable_libstdcxx_filesystem_ts=no
         ;;

libstdc++-v3/configure

@@ -74551,6 +74551,9 @@ $as_echo_n "checking whether to build Filesystem TS support... " >&6; }
       solaris*)
         enable_libstdcxx_filesystem_ts=yes
         ;;
+      mingw*)
+        enable_libstdcxx_filesystem_ts=yes
+        ;;
       *)
         enable_libstdcxx_filesystem_ts=no
         ;;