graphqlbackend: Reduce allocations in getRevsForMatchedRepo
Created by: tsenart
name old time/op new time/op delta
SearchResults-16 5.37ms ±23% 4.57ms ±18% -14.97% (p=0.001 n=10+10)
name old alloc/op new alloc/op delta
SearchResults-16 1.97MB ± 0% 1.73MB ± 0% -12.40% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
SearchResults-16 15.6k ± 0% 10.6k ± 0% -32.04% (p=0.000 n=10+6)