clean up the users of PL_no_mem

clean up the users of PL_no_mem

This commit eliminates a couple strlen()s of a literal. "Out of memory!\n"
and PL_no_mem did not string pool on Visual C, so PL_no_mem was given a
length. This commit removes S_write_no_mem and replaces it with nonstatic.
Perl_croak_no_mem was made nocontext to save instructions in it's callers.
NORETURN_FUNCTION_END caused a syntax error on Visual C C++ mode and
therefore was removed.