doc/install.texi: add documentation for --disable-libsanitizer

This patch adds an item for --disable-libsanitizer to the configuration
documentation.
The option is especially useful during bisection, because it reduces
build time a lot.

2014-09-15  Markus Trippelsdorf  <markus@trippelsdorf.de>

	* doc/install.texi (Options specification): add
	--disable-libsanitizer item.

From-SVN: r215259

gcc/ChangeLog

+2014-09-15  Markus Trippelsdorf  <markus@trippelsdorf.de>
+
+	* doc/install.texi (Options specification): add 
+	--disable-libsanitizer item.
+
 2014-09-14  James Clarke  <jrtc27@jrtc27.com>
 	    Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
 

gcc/doc/install.texi

@@ -1451,6 +1451,10 @@ be built.  This can be useful for debugging, or for compatibility with
 previous Ada build procedures, when it was required to explicitly
 do a @samp{make -C gcc gnatlib_and_tools}.
 
+@item --disable-libsanitizer
+Specify that the run-time libraries for the various sanitizers should
+not be built.
+
 @item --disable-libssp
 Specify that the run-time libraries for stack smashing protection
 should not be built.