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/atlocal.in

@@ -69,7 +69,7 @@ if $BISON_CXX_WORKS; then
 
 int main ()
 {
-  std::cout << "Works" << std::endl;
+  std::cout << "Works\n";
 }
 EOF
   $CXX $CXXFLAGS $CPPFLAGS $LDFLAGS $LIBS -o conftest conftest.cc