deduction.cc: Avoid -Wreturn-type warnings.

deduction.cc: Avoid -Wreturn-type warnings.

2017-11-06  Paolo Carlini  <paolo.carlini@oracle.com>

	* testsuite/20_util/optional/cons/deduction.cc: Avoid -Wreturn-type
	warnings.
	* testsuite/20_util/pair/cons/deduction.cc: Likewise.
	* testsuite/20_util/pair/traits.cc: Likewise.
	* testsuite/20_util/tuple/cons/deduction.cc: Likewise.
	* testsuite/20_util/variant/compile.cc: Likewise.
	* testsuite/23_containers/map/modifiers/try_emplace/1.cc: Likewise.
	* testsuite/23_containers/unordered_map/modifiers/try_emplace.cc:
	Likewise.

From-SVN: r254450