* doc/invoke.text (--help): Document --help=common.

From-SVN: r123769

gcc/ChangeLog

+2007-04-12  Brooks Moses  <brooks.moses@codesourcery.com>
+
+	* doc/invoke.text (--help): Document --help=common.
+
 2007-04-12  Thomas Neumann  <tneumann@users.sourceforge.net>
 
 	* stub-objc.c (objc_build_keyword_decl): Avoid C++ keywords.

gcc/doc/invoke.texi

@@ -1128,6 +1128,9 @@ option.
 This will display the options supported for @var{language}, where 
 @var{language} is the name of one of the languages supported in this 
 version of GCC.
+
+@item @samp{common}
+This will display the options that are common to all languages.
 @end table
 
 It is possible to further refine the output of the @option{--help=}