Otherwise, Google Test will insist on inserting 'char8_t' NTBS into 'char' streams, but basic_ostream<char>::operator<< overloads taking 'char8_t' arguments are defined as deleted by P1423.
Handling individual 'char8_t's is done inline.
This fixes the compilation errors seen in C++20 mode beginning with VS2019 Update 2.
Signed-off-by: Daniela Engert <dani@ngrt.de>