Modernize usage of 'macOS' in doc and comments

Apple changed the spelling of its operating system again, to "macOS",
effective with macOS 10.12 Sierra (2016-09-20).  Change Emacs
documentation and comments to match this.  Stick with older OS
spellings ("OS X", "Mac OS X") when talking about older releases where
the older names are more correct.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/frame.c b/src/frame.c
index cfa5f7d5027..854f72e64b4 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -5088,7 +5088,7 @@ Setting this variable does not affect existing frames, only new ones.  */);
                doc: /* Default position of vertical scroll bars on this window-system.  */);
 #ifdef HAVE_WINDOW_SYSTEM
 #if defined (HAVE_NTGUI) || defined (NS_IMPL_COCOA) || (defined (USE_GTK) && defined (USE_TOOLKIT_SCROLL_BARS))
-  /* MS-Windows, Mac OS X, and GTK have scroll bars on the right by
+  /* MS-Windows, macOS, and GTK have scroll bars on the right by
      default.  */
   Vdefault_frame_scroll_bars = Qright;
 #else