Also test -std=c++0x mode with 'make check-c++' at top level
* Makefile.in (check-gcc-c++0x): New.
(check-c++): Depend on it.
gcc/
* Makefile.in ($(lang_checks_parallelized)): Allow --tool_opts.
gcc/cp/
* Make-lang.in (check-c++0x): New.
gcc/testsuite/
* lib/g++.exp (${tool}_option_help, ${tool}_option_proc): Remove.
* lib/lto.exp (lto_prune_warns): Prune warning about -std=c++0x
when compiling C files.
From-SVN: r176250
