install.texi (Options specification): Restore entry of --enable-sjlj-exceptions.

	* doc/install.texi (Options specification): Restore entry of
	--enable-sjlj-exceptions.

From-SVN: r248582

gcc/ChangeLog

+2017-05-29  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* doc/install.texi (Options specification): Restore entry of
+	--enable-sjlj-exceptions.
+
 2017-05-27  Michael Eager  <eager@eagercon.com>
 
 	Revert:

gcc/doc/install.texi

@@ -1047,6 +1047,11 @@ and for cross builds configured with @option{--with-sysroot}, and without
 More documentation about multiarch can be found at
 @uref{https://wiki.debian.org/Multiarch}.
 
+@item --enable-sjlj-exceptions
+Force use of the @code{setjmp}/@code{longjmp}-based scheme for exceptions.
+@samp{configure} ordinarily picks the correct value based on the platform.
+Only use this option if you are sure you need a different setting.
+
 @item --enable-vtable-verify
 Specify whether to enable or disable the vtable verification feature.
 Enabling this feature causes libstdc++ to be built with its virtual calls