More #include suggestions (PR c++/84269)

More #include suggestions (PR c++/84269)

PR c++/84269 reports a number of names in the C and C++ standard
libraries for which we don't yet offer #include fix-it hints.

This patch adds them (up to comment #9).

gcc/c-family/ChangeLog:
	PR c++/84269
	* known-headers.cc (get_stdlib_header_for_name): Add various names
	from <assert.h>, <string.h>, and <memory.h>; add more names from
	<stdio.h>.

gcc/cp/ChangeLog:
	PR c++/84269
	* name-lookup.c (get_std_name_hint): Add names from <memory>,
	<tuple>, and <utility>.

gcc/testsuite/ChangeLog:
	PR c++/84269
	* g++.dg/lookup/missing-std-include-6.C: New test.
	* g++.dg/lookup/missing-std-include.C: Add std::pair and
	std::tuple tests.
	* g++.dg/spellcheck-reswords.C: Expect a hint about <cstring>.
	* g++.dg/spellcheck-stdlib.C: Add tests for names in <cstdio>,
	<cstring>, <cassert>, and <cstdlib>.

From-SVN: r258966