As the audit trail of this shows, -Wunused-local-typedefs is not
turned on by -Wunused after all.  Sigh.

Now that we have the EnabledBy construct for the *.opt files, it's
more precise and concise to use that to make -Wunused-local-typedefs
be triggered by -Wunused.

I have changed the gcc+.dg/warn/Wunused-local-typedefs.C test case to
make it use -Wunused instead of -Wunused-local-typedefs.  I had to
adjust it to avoid the warnings due to the other -W* options triggered
by -Wunused there.

While testing the compiler, it turned out that some local typedefs
were not being used when the experimental "Concepts" support is turned
off, in the libstdc++ test suite.  I also had to remove some obvious
useless local typedef usage in the fortran front-end.  Fixed thus.

Bootstrapped and tested on x86_64-unknown-linux-gnu against trunk.

gcc/c-family/

	PR c++/53322
	* c.opt (Wunused-local-typedefs): Use EnabledBy(Wunused).

libstdc++-v3/

	PR c++/53322
	* include/bits/stl_algobase.h (lower_bound)
	(lexicographical_compare): Do not declare unused local typedefs
	here when Concepts are turned off.

gcc/fortran/

	PR c++/53322
	* f95-lang.c (gfc_init_builtin_functions): Remove the unused
	typedef builtin_type.

gcc/testsuite/

	PR c++/53322
	* g++.dg/warn/Wunused-local-typedefs.C: Adjust to use -Wunused
	instead of -Wunused-local-typedefs.

From-SVN: r187757