[dev.link] cmd/internal: remove unneeded RefIdx field

Change-Id: Ic77e67b70b76dc958890e74b77c9691c30eb6ba1
Reviewed-on: https://go-review.googlesource.com/c/go/+/220060
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

src/cmd/internal/obj/link.go

@@ -381,7 +381,6 @@ type LSym struct {
 	Type objabi.SymKind
 	Attribute
 
-	RefIdx int // Index of this symbol in the symbol reference list.
 	Size   int64
 	Gotype *LSym
 	P      []byte
@@ -391,7 +390,7 @@ type LSym struct {
 
 	Pkg    string
 	PkgIdx int32
-	SymIdx int32 // TODO: replace RefIdx
+	SymIdx int32
 }
 
 // A FuncInfo contains extra fields for STEXT symbols.

src/cmd/internal/obj/sizeof_test.go

@@ -21,7 +21,7 @@ func TestSizeof(t *testing.T) {
 		_64bit uintptr     // size on 64bit platforms
 	}{
 		{Addr{}, 32, 48},
-		{LSym{}, 76, 128},
+		{LSym{}, 72, 120},
 		{Prog{}, 132, 200},
 	}