install.texi: Correct description of default directory for --with-gxx-include-dir.

	* doc/install.texi: Correct description of default directory for
	--with-gxx-include-dir.

From-SVN: r145996

gcc/ChangeLog

+2009-04-12  Mark Mitchell  <mark@codesourcery.com>
+
+	* doc/install.texi: Correct description of default directory for
+	--with-gxx-include-dir.
+
 2009-04-12 Eric Botcazou <ebotcazou@adacore.com>
 
 	* fold-const.c (build_range_check): Properly deal with enumeral and

gcc/doc/install.texi

@@ -720,8 +720,9 @@ manual.)
 
 @item --with-gxx-include-dir=@var{dirname}
 Specify
-the installation directory for G++ header files.  The default is
-@file{@var{prefix}/include/c++/@var{version}}.
+the installation directory for G++ header files.  The default depends
+on other configuration options, and differs between cross and native
+configurations.
 
 @end table