fix for 37: performance regression in 3.1
fix for 37: performance regression in 3.1

mafiya69/fsharp,bleis-tift/FSharp.Compiler.Service,alfonsogarciacaro/FSharp.Compiler.Service,dsyme/FSharp.Compiler.Service,brettfo/visualfsharp,Jand42/FSharp.Compiler.Service,rneatherway/FSharp.Compiler.Service,jeroldhaas/FSharp.Compiler.Service,forki/fsharp,brettfo/visualfsharp,dsyme/fsharp,Jand42/FSharp.Compiler.Service,matthid/FSharp.Compiler.Service,fsharp/fsharp,syeerzy/visualfsharp,brettfo/visualfsharp,dsyme/fsharp,yever/FSharp.Compiler.Service,dsyme/fsharp,vasily-kirichenko/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,rolfbjarne/fsharp,eloraiby/fsharp,In2TheWild/fsharp,forki/fsharp,enricosada/fsharp,matthid/FSharp.Compiler.Service,alexischr/fsharp,0x53A/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,dsyme/FSharp.Compiler.Service,alexischr/fsharp,directhex/fsharp,rojepp/FSharp.Compiler.Service,fsharp/fsharp,Heather/fsharp,syeerzy/visualfsharp,syeerzy/visualfsharp,sergey-tihon/FSharp.Compiler.Service,syeerzy/visualfsharp,sergey-tihon/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,alexischr/fsharp,forki/FSharp.Compiler.Service,forki/FSharp.Compiler.Service,forki/FSharp.Compiler.Service,bleis-tift/FSharp.Compiler.Service,dsyme/fsharp,matthid/FSharp.Compiler.Service,syeerzy/visualfsharp,alfonsogarciacaro/FSharp.Compiler.Service,wk-j/fsharp,7sharp9/fsharp,BillHally/FSharp.Compiler.Service,directhex/fsharp,dsyme/fsharp,cloudRoutine/FSharp.Compiler.Service,brettfo/visualfsharp,rolfbjarne/fsharp,enricosada/fsharp,mafiya69/fsharp,dsyme/fsharp,rneatherway/FSharp.Compiler.Service,fsharp/fsharp,brettfo/visualfsharp,Jand42/FSharp.Compiler.Service,yever/FSharp.Compiler.Service,rojepp/FSharp.Compiler.Service,vasily-kirichenko/FSharp.Compiler.Service,Heather/fsharp,eloraiby/fsharp,brettfo/visualfsharp,sergey-tihon/FSharp.Compiler.Service,7sharp9/fsharp,syeerzy/visualfsharp,rojepp/FSharp.Compiler.Service,jeroldhaas/FSharp.Compiler.Service,BillHally/FSharp.Compiler.Service,0x53A/FSharp.Compiler.Service,0x53A/FSharp.Compiler.Service,vasily-kirichenko/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,dsyme/FSharp.Compiler.Service,wk-j/fsharp,alfonsogarciacaro/FSharp.Compiler.Service,dsyme/fsharp,In2TheWild/fsharp