clover: Add explicit handling of denormals
New target-independent handling of denormals was added in llvm/clang 11. Add device query for fp32 denormals and use it to both expose the feature and pass the correct compiler options.
New target-independent handling of denormals was added in llvm/clang 11. Add device query for fp32 denormals and use it to both expose the feature and pass the correct compiler options.