cmd/compile: remove duplicates by using finishcompare

Updates #23834

Change-Id: If05001f9fd6b97d72069f440102eec6e371908dd
Reviewed-on: https://go-review.googlesource.com/97016
Run-TryBot: Kunpei Sakai <namusyaka@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

src/cmd/compile/internal/gc/walk.go

@@ -1700,10 +1700,7 @@ opswitch:
 		} else {
 			cmp = nod(OOROR, nod(ONE, lt, rt), nod(ONOT, call, nil))
 		}
-		cmp = typecheck(cmp, Erv)
-		cmp = walkexpr(cmp, init)
-		cmp.Type = n.Type
-		n = cmp
+		n = finishcompare(n, cmp, init)
 
 	case OARRAYLIT, OSLICELIT, OMAPLIT, OSTRUCTLIT, OPTRLIT:
 		if isStaticCompositeLiteral(n) && !canSSAType(n.Type) {