[ruby/irb] Add a space before left paren

https://github.com/ruby/irb/commit/973bac83ff

lib/irb.rb

@@ -62,7 +62,7 @@ require_relative "irb/easter-egg"
 #     -W[level=2]       Same as `ruby -W`
 #     --context-mode n  Set n[0-4] to method to create Binding Object,
 #                       when new workspace was created
-#     --echo            Show result(default)
+#     --echo            Show result (default)
 #     --noecho          Don't show result
 #     --inspect         Use `inspect' for output
 #     --noinspect       Don't use inspect for output

lib/irb/lc/help-message

@@ -20,7 +20,7 @@ Usage:  irb.rb [options] [programfile] [arguments]
   -W[level=2]       Same as `ruby -W`
   --context-mode n  Set n[0-4] to method to create Binding Object,
                     when new workspace was created
-  --echo            Show result(default)
+  --echo            Show result (default)
   --noecho          Don't show result
   --inspect         Use `inspect' for output
   --noinspect       Don't use inspect for output

man/irb.1

@@ -106,7 +106,7 @@ Doesn't use singleline editor module.
 .Pp
 .Pp
 .It Fl -echo
-Show result(default).
+Show result (default).
 .Pp
 .It Fl -noecho
 Don't show result.