[SYCL] Fix marray math function impls (#6038)

This PR aims to fix issue: #5991
and provide efficient working marray math function implementations for
all backends.

marray math function support is currently switched on for {n} ({n}
defined in #5991) but the implementations are currently broken and
untested. There is also very limited test coverage for sycl::vec cases.
The SYCL 2020 specification states that the set {N} ({N} defined in
#5991) should be supported for marray math function cases.

All SYCL 2020 math, native math, and half_precision math functions now
have marray support when the function's arguments are of type `genfloat`
and have the same argument type for all arguments.

Tests: intel/llvm-test-suite#1002

Signed-off-by: jack.kirk <jack.kirk@codeplay.com>
Co-authored-by: JackAKirk <chezjakirk@gmail.com>
Co-authored-by: Jakub Chlanda <jakub@codeplay.com>

Author: 3 people