The `--enable-version-specific-runtime-libs' configuration option is now
supported throughout all of our target library subdirectories, so update
installation documentation accordingly and also mention that the default
for the option is `yes' for libada and `no' for the remaining libraries.

	gcc/
	* doc/install.texi (Options specification): Remove the list of
	target library subdirectories supporting
	`--enable-version-specific-runtime-libs'.  Document defaults for
	the option.

From-SVN: r278871