`spirv-link` seems to internalize all symbols, which ends up causing the
OpenMP Device Environment global generated by the OMP FE to get
optimized out which causes `liboffload` to run in the wrong
parallelization mode which breaks at least one liboffload lit test.
Pass `--create-library` to tell it not to do that.
```
--create-library
Link the binaries into a library, keeping all exported symbols.
```
This fixes the test.
Closes: https://github.com/llvm/llvm-project/issues/182901
Signed-off-by: Nick Sarnie <nick.sarnie@intel.com>