cmd/compile: remove unused code

Found a few functions in cmd/compile that aren't used.

Change-Id: I53957dae6f1a645feb8b95383f0f050964b4f7d4
Reviewed-on: https://go-review.googlesource.com/79975
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

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

@@ -109,19 +109,6 @@ func hidePanic() {
 	}
 }
 
-func doversion() {
-	p := objabi.Expstring()
-	if p == objabi.DefaultExpstring() {
-		p = ""
-	}
-	sep := ""
-	if p != "" {
-		sep = " "
-	}
-	fmt.Printf("compile version %s%s%s\n", objabi.Version, sep, p)
-	os.Exit(0)
-}
-
 // supportsDynlink reports whether or not the code generator for the given
 // architecture supports the -shared and -dynlink flags.
 func supportsDynlink(arch *sys.Arch) bool {

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

@@ -2227,32 +2227,6 @@ func iscallret(n *Node) bool {
 	return n.Op == OINDREGSP
 }
 
-func isstack(n *Node) bool {
-	n = outervalue(n)
-
-	// If n is *autotmp and autotmp = &foo, replace n with foo.
-	// We introduce such temps when initializing struct literals.
-	if n.Op == OIND && n.Left.Op == ONAME && n.Left.IsAutoTmp() {
-		defn := n.Left.Name.Defn
-		if defn != nil && defn.Op == OAS && defn.Right.Op == OADDR {
-			n = defn.Right.Left
-		}
-	}
-
-	switch n.Op {
-	case OINDREGSP:
-		return true
-
-	case ONAME:
-		switch n.Class() {
-		case PAUTO, PPARAM, PPARAMOUT:
-			return true
-		}
-	}
-
-	return false
-}
-
 // isReflectHeaderDataField reports whether l is an expression p.Data
 // where p has type reflect.SliceHeader or reflect.StringHeader.
 func isReflectHeaderDataField(l *Node) bool {

src/cmd/compile/internal/ssa/rewrite.go

@@ -117,10 +117,6 @@ func isSigned(t *types.Type) bool {
 	return t.IsSigned()
 }
 
-func typeSize(t *types.Type) int64 {
-	return t.Size()
-}
-
 // mergeSym merges two symbolic offsets. There is no real merging of
 // offsets, we just pick the non-nil one.
 func mergeSym(x, y interface{}) interface{} {