[v3 PATCH] Implement P0403R1, Literal suffixes for basic_string_view.

[Jonathan Wakely]

On 13/11/16 22:41 +0200, Ville Voutilainen wrote:
>    Implement P0403R1, Literal suffixes for basic_string_view.
>    * include/std/string_view
>    (operator""sv(const char*, size_t)): New.
>    (operator""sv(const wchar_t*, size_t)): Likewise.
>    (operator""sv(const char16_t*, size_t)): Likewise.
>    (operator""sv(const char32_t*, size_t)): Likewise.
>    * testsuite/21_strings/basic_string_view/literals/types.cc: New.
>    * testsuite/21_strings/basic_string_view/literals/values.cc: Likewise.
>    * testsuite/experimental/string_view/literals/values.cc: Add
>    tests for literals with embedded NULs.

OK for trunk, thanks.