style: don't use std::endl

* data/lalr1.cc, doc/bison.texi, etc/bench.pl.in, examples/variant.yy,
* tests/actions.at, tests/atlocal.in, tests/c++.at, tests/headers.at,
* tests/local.at, tests/types.at:
Don't use std::endl, it flushes uselessly, and is considered bad
style.

tests/actions.at

@@ -203,7 +203,7 @@ AT_DATA_GRAMMAR([[input.y]],
 ]AT_YYLEX_DECLARE[
 }
 %%
-exp: { ]AT_SKEL_CC_IF([[std::cerr << @$ << std::endl]],
+exp: { ]AT_SKEL_CC_IF([[std::cerr << @$ << '\n']],
                       [[LOCATION_PRINT(stderr, @$); fputc ('\n', stderr)]])[; }
 %%
 ]AT_YYERROR_DEFINE[