Add support for `fp64_gen_emu` also in API options #4250

Job	Run time
download-OpenCL-Clang	8s
build-SPIRV-LLVM-Translator (20.04, 14)	14s
build-SPIRV-LLVM-Translator (22.04, 14)	10s
build-SPIRV-LLVM-Translator (22.04, 15, true)	9s
build-IGC (20.04, 14, gcc)	56m 44s
build-IGC (20.04, 14, clang)	30m 23s
build-IGC (22.04, 14, gcc)	48m 27s
build-IGC (22.04, 14, clang)	37m 17s
build-IGC (22.04, 15, gcc, true)	43m 8s
	3h 36m 40s

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