patch 8.0.0464: can't find executable name on Solaris and FreeBSD

Problem:    Can't find executable name on Solaris and FreeBSD.
Solution:   Check for "/proc/self/path/a.out". (Danek Duvall) And for
            "/proc/curproc/file".
diff --git a/src/version.c b/src/version.c
index c1ac29d..efef5f8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    464,
+/**/
     463,
 /**/
     462,