patch 8.1.0347: some tests fail on Solaris

Problem:    Some tests fail on Solaris.
Solution:   Skip writefile test. Fix path to libc.so. Improve test for Turkish
            case change. (Libor Bukata, Bjorn Linse, closes #3403)
diff --git a/src/version.c b/src/version.c
index b0ed507..790cd76 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    347,
+/**/
     346,
 /**/
     345,