libstdc++: Do not use def-file-line for each macro in <bits/version.h>

libstdc++: Do not use def-file-line for each macro in <bits/version.h>

These line markers are not needed, because searching <bits/version.def>
for a macro name works fine. Removing them means that small changes to
<bits/version.def> do not result in large diffs to <bits/version.h>
because of all the changed line numbers.

libstdc++-v3/ChangeLog:

	* include/bits/version.tpl: Do not use def-file-line for each
	macro being defined.
	* include/bits/version.h: Regenerate.