Fix regression for FS0725

[edgarfgp]

As discovered by failing test on FsAutoComplete in F# 8 we no longer show FS0725 in cases where it is supposed to.

moduleTeststypeA={ X:int }typeB= B ofintmatch None with| None 1->()// FS0725match None with| None (1,2)->()// FS0725match None with| None []->()// FS0725match None with| None [||]->()// FS0725match None with| None { X =1}->()// FS0725match None with| None (B 1)->()// FS0725match None with| None (x, y)->()// FS0725match None with| None false->()// FS0725match None with| None x ->()//FS0725match None with| None _->()// F#7 this compiles. In F#8 this shows FS3548typeC=| C
letmyDiscardedArgFunc(C _)=()// F#7 this compiles. In F#8 this shows FS3548letmyDiscardedArgFunc2(C c)=()// FS0725

PR that introduced the regression #14055

[edgarfgp]

On a second look while working on this fix. I think for

match None with| None x ->()// In F#8 this shows Warning FS3548 instead of Error FS0725 ? I think is should as it was in F#7typeC=| C
letmyDiscardedArgFunc2(C c)=()// In F#8 this shows Warning FS3548 instead of Error FS0725 ? I think is should be as it was in F#7

Any thoughts? cc @vzarytovskii

[vzarytovskii]

On a second look while working on this fix. I think for

match None with| None x ->()// In F#8 this shows Warning FS3548 instead of Error FS0725 ? I think is should as it was in F#7typeC=| C
letmyDiscardedArgFunc2(C c)=()// In F#8 this shows Warning FS3548 instead of Error FS0725 ? I think is should be as it was in F#7

Any thoughts? cc @vzarytovskii

Yeah, I guess we shouldn't downgrade error to warning here.

[edgarfgp]

On a second look while working on this fix. I think for

match None with| None x ->()// In F#8 this shows Warning FS3548 instead of Error FS0725 ? I think is should as it was in F#7typeC=| C
letmyDiscardedArgFunc2(C c)=()// In F#8 this shows Warning FS3548 instead of Error FS0725 ? I think is should be as it was in F#7

Any thoughts? cc @vzarytovskii

Yeah, I guess we shouldn't downgrade error to warning here.

Also the FS3548 error message does not really match what is happening here

Update: FS3548 imo is really about discard _

[edgarfgp]

This is ready