Minor cleanup: omit nil as the value of definitions
Minor cleanup: omit nil as the value of definitions

laarc/lumen,shawwn/lumen,laarc/lumen-contrib,sctb/lumen,laarc/lumen-contrib,elflang/elf,sctb/lumen,laarc/lumen-contrib,shawwn/lumen,elflang/elf,laarc/lumen,laarc/lumen,sctb/lumen,elflang/elf,shawwn/lumen,shawwn/lumen