Fix CTests in SYCL runs

[amametjanov]

Fix CTests in SYCL runs:

• Move -Xsycl-target-backend to link flags
• Fix SYCL and PBS flags

Checklist

• Testing
  • A comment in the PR documents testing used to verify the changes including any tests that are added/modified/impacted.
  • Unit tests have passed. Please provide a relevant CDash build entry for verification.

[amametjanov]

Testing:

• most of the tests are passing for both oneapi-ifx on CPUs and oneapi-ifxgpu on GPUs.
• need to fix IO_TEST: NetCDF _FillValue type mismatch error

96% tests passed, 1 tests failed out of 28 

Total Test time (real) = 179.80 sec

The following tests FAILED:
         15 - IO_TEST (Failed)

[grnydawn]

Please see my comments below.

[grnydawn]

We want to add the "OMEGA_" prefix to all Omega-related CMake variables and prefer using "OMEGA_SYCL_FLAGS" instead of "SYCL_FLAGS."

[amametjanov]

Adding generic SYCL flags from upstream-E3SM here. Omega-specific flags are added with OMEGA_SYCL_EXE_LINKER_FLAGS .

[grnydawn]

I guess that SYCL_FLAGS is defined somewhere in E3SM (or CIME). Do you allow users to add -DSYCL_FLAGS in the Omega CMake command line for standalone build? If allowed, I think we may still want to use OMEGA_SYCL_FLAGS in addition to SYCL_FLAGS for naming consistency similar to:

if(SYCL_FLAGS)
   set(OMEGA_SYCL_FLAGS "${OMEGA_SYCL_FLAGS} ${SYCL_FLAGS}")
endif()

[amametjanov]

Yes, SYCL_FLAGS is coming from E3SM's cime_config/machines/cmake_macros/oneapi-ifxgpu_$MACHINE.cmake. I added a commit to keep OMEGA_SYCL_FLAGS .

[amametjanov]

This PR depends on E3SM-Project#6715 : E3SM tests with cmake changes in this PR appear to be okay. I'll update as soon as this PR is ready.

[amametjanov]

@grnydawn please see below: I tried to address all of the comments, thanks.

[amametjanov]

Adding generic SYCL flags from upstream-E3SM here. Omega-specific flags are added with OMEGA_SYCL_EXE_LINKER_FLAGS .

[grnydawn]

Approved. All tests on Frontier and Chrysalis have passed. We can revisit the SYCL_FLAGS discussion if needed in the future. Thanks!