There is no problem in using the "insecure" CRT functions, as long as
they are used correctly - especially not within the test suite where
they are only are exposed to the test suite input data.
Within the library, these are used via the library internal wrappers
in codec/common/src/crt_util_safe_x.cpp, but we'd rather not use them
in the test suite - just use the normal standard C functions here.
This disables armasm warning A4509, "This form of conditional
instruction is deprecated".
The conditional instructions (such as movcs, addcs, subscs)
have been deprecated in ARMv8, in favor of conditional branches.
This isn't something that we need to take immediate action about,
though, therefore silence the warning.
This makes it clearer which ones actually are real platforms
(chosen automatically or explicitly via "make ARCH=foo") and which
ones just are shared helpers.
