Update runtime files.
diff --git a/runtime/doc/os_mac.txt b/runtime/doc/os_mac.txt
index 2a2b07a..226d3ba 100644
--- a/runtime/doc/os_mac.txt
+++ b/runtime/doc/os_mac.txt
@@ -1,4 +1,4 @@
-*os_mac.txt* For Vim version 8.0. Last change: 2017 Apr 28
+*os_mac.txt* For Vim version 8.0. Last change: 2018 Jan 21
VIM REFERENCE MANUAL by Bram Moolenaar et al.
@@ -165,7 +165,7 @@
To make sure at runtime whether or not the darwin feature is compiled in, you
can use `has('osxdarwin')` which returns 1 if the feature is compiled in; 0
-otherwise. For backwards comptibility, you can still use `macunix` instead of
+otherwise. For backward compatibility, you can still use `macunix` instead of
`osxdarwin`.
Notable use cases where `--disable-darwin` is turned out to be useful are: