patch 8.0.1849: compiler warning for unused arguments, missing prototype

Problem:    compiler warning for unused arguments and missing prototype
Solution:   Add UNUSED.  Add static.

Author: brammool

src/if_ruby.c

@@ -828,7 +828,7 @@ void ex_rubydo(exarg_T *eap)
     }
 }
 
-VALUE rb_load_wrap(VALUE file_to_load)
+static VALUE rb_load_wrap(VALUE file_to_load)
 {
     rb_load(file_to_load, 0);
     return Qnil;

src/mbyte.c

@@ -6506,7 +6506,7 @@ im_set_active(int active_arg)
 
 #  ifdef FEAT_GUI
     void
-im_set_position(int row, int col)
+im_set_position(int row UNUSED, int col UNUSED)
 {
 }
 #  endif

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1849,
 /**/
     1848,
 /**/