[libspirv] Convert __assert_fail.ll and image_helpers.ll to CL files (#21547)
LLVM IR (.ll) files doesn't work with cmake add_library change in
libclc.
image_helpers.cl PTX output verified against reference PTX generated
from image_helpers.ll.
Bindless image tests passed (no regressions) on NV 2060.
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Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>
Co-authored-by: Mészáros Gergely <maetveis@gmail.com>
Co-authored-by: Meszaros, Gergely <gergely.meszaros@intel.com>