t/TEST shouldn't use -M options until we've tested that they work.

t/TEST shouldn't use -M options until we've tested that they work.

Also, t/TEST doesn't need to set $ENV{PERL_CORE} as t/TestInit.pm does this.
t/TestInit.pm should also add '.' to @INC (except under tainting) to correctly
emulate the include path of this perl binary once it and its libraries are
installed.

Fix t/run/cloexec.t to not rely on -I../lib being passed as a command-line
arguments. t/run/*.t *test* that command line arguments work, so they can't
be called with command line arguments that are mandatory for them to work.