Handle the smoothstep degenerate case of empty range #36727

Job	Run time
📊 Static checks / Code style, file formatting, and docs	37s
🍎 macOS / Editor (target=editor, tests=yes)	24m 24s
🍎 macOS / Template (target=template_release)	17m 12s
🍏 iOS / Template (target=template_release)	10m 23s
🤖 Android / Editor (target=editor)	21m 47s
🐧 Linux / Editor w/ Mono (target=editor)	35m 16s
🤖 Android / Template arm32 (target=template_release, arch=arm32)	14m 8s
🐧 Linux / Editor with doubles and GCC sanitizers (target=editor, tests=yes, dev_build=yes, scu_build=yes, precision=double, use_asan=yes, use_ubsan=yes, linker=gold)	38m 48s
🤖 Android / Template arm64 (target=template_release, arch=arm64)	16m 5s
🌐 Web / Template w/ threads (target=template_release, threads=yes)	22m 34s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	31m 10s
🏁 Windows / Editor (target=editor, tests=yes)	42m 21s
🌐 Web / Template w/o threads (target=template_release, threads=no)	22m 55s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	28m 2s
🏁 Windows / Template (target=template_release)	30m 11s
🐧 Linux / Template w/ Mono (target=template_release)	21m 22s
🐧 Linux / Minimal template (target=template_release, everything disabled)	15m 12s
🪲 Godot CPP / Build and test Godot CPP	8m 13s
	6h 40m 40s

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