[SYCL] Changed USM copy src and dst parameter order

[dnmokhov]

As noted in #3897 (comment),
a spec bug was identified. The USM copy member functions take the src
and dst parameters in the wrong order. The order should be (src, dst),
which matches the standard C++ copy function and matches the existing
SYCL copy functions that take accessor parameters.

Tests: intel/llvm-test-suite#342

[dnmokhov]

There are currently no tests in https://github.com/intel/llvm-test-suite for the newly-added copy. I am working on them and will update them to use the new version before posting a pull request.

[gmlueck]

Thanks, LGTM.

FYI: @mkinsner @jbrodman
This changes the order of the USM copy parameters as we discussed.

[mkinsner]

LGTM

[bader]

@intel/llvm-reviewers-runtime, ping.

[s-kanaev]

LGTM

[s-kanaev]

Will this change break API compatibility?
That is, when compiling existing application source, the dst and src are in different order than expected.

Wrong review.

[sergey-semenov]

Will this change break API compatibility?
That is, when compiling existing application source, the dst and src are in different order than expected.

These functions have only been added in #3897, so we should be fine here (unless we care about maintaining API compatibility not just between releases, but also between commits).

[s-kanaev]

These functions have only been added in #3897, so we should be fine here (unless we care about maintaining API compatibility not just between releases, but also between commits).

Sounds OK to me, then.