In a modules build, android is very picky about which symbols are
visible after including libc++ headers (e.g. <cstdio> defines only
std::printf and not ::printf).
This consolidates the tests where this was an issue to always include
the <c???> version of the headers and prefixes the symbols with std:: as
necessary.
Apart from that, there is no functional change in the tests.
llvm-svn: 335149
0583d7a56c