cmd/compile: remove typecheck.Orig* functions

Same as CL 526397, but for typecheck.

Change-Id: Ia8f19a54ffaa2ae3b86a4c66cbe6d973482796cd
Reviewed-on: https://go-review.googlesource.com/c/go/+/526236
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

src/cmd/compile/internal/loopvar/loopvar.go

@@ -355,26 +355,17 @@ func ForCapture(fn *ir.Func) []VarAndLoop {
 					})
 
 					postNotNil := x.Post != nil
-					var tmpFirstDcl *ir.AssignStmt
+					var tmpFirstDcl ir.Node
 					if postNotNil {
 						// body' = prebody +
 						// (6)     if tmp_first {tmp_first = false} else {Post} +
 						//         if !cond {break} + ...
 						tmpFirst := typecheck.TempAt(base.Pos, fn, types.Types[types.TBOOL])
-
-						// tmpFirstAssign assigns val to tmpFirst
-						tmpFirstAssign := func(val bool) *ir.AssignStmt {
-							s := ir.NewAssignStmt(x.Pos(), tmpFirst, typecheck.OrigBool(tmpFirst, val))
-							s.SetTypecheck(1)
-							return s
-						}
-
-						tmpFirstDcl = tmpFirstAssign(true)
-						tmpFirstDcl.Def = true // also declares tmpFirst
-						tmpFirstSetFalse := tmpFirstAssign(false)
+						tmpFirstDcl = typecheck.Stmt(ir.NewAssignStmt(x.Pos(), tmpFirst, ir.NewBool(base.Pos, true)))
+						tmpFirstSetFalse := typecheck.Stmt(ir.NewAssignStmt(x.Pos(), tmpFirst, ir.NewBool(base.Pos, false)))
 						ifTmpFirst := ir.NewIfStmt(x.Pos(), tmpFirst, ir.Nodes{tmpFirstSetFalse}, ir.Nodes{x.Post})
-						ifTmpFirst.SetTypecheck(1)
-						preBody.Append(ifTmpFirst)
+						ifTmpFirst.PtrInit().Append(typecheck.Stmt(ir.NewDecl(base.Pos, ir.ODCL, tmpFirst))) // declares tmpFirst
+						preBody.Append(typecheck.Stmt(ifTmpFirst))
 					}
 
 					// body' = prebody +

src/cmd/compile/internal/staticinit/sched.go

@@ -1033,7 +1033,7 @@ func addStr(n *ir.AddStringExpr) ir.Node {
 		for _, c := range s {
 			strs = append(strs, ir.StringVal(c))
 		}
-		return typecheck.OrigConst(n, constant.MakeString(strings.Join(strs, "")))
+		return ir.NewConstExpr(constant.MakeString(strings.Join(strs, "")), n)
 	}
 	newList := make([]ir.Node, 0, need)
 	for i := 0; i < len(s); i++ {
@@ -1046,9 +1046,7 @@ func addStr(n *ir.AddStringExpr) ir.Node {
 				i2++
 			}
 
-			nl := ir.Copy(n).(*ir.AddStringExpr)
-			nl.List = s[i:i2]
-			newList = append(newList, typecheck.OrigConst(nl, constant.MakeString(strings.Join(strs, ""))))
+			newList = append(newList, ir.NewConstExpr(constant.MakeString(strings.Join(strs, "")), s[i]))
 			i = i2 - 1
 		} else {
 			newList = append(newList, s[i])

src/cmd/compile/internal/typecheck/const.go

@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"go/constant"
 	"go/token"
-	"internal/types/errors"
 	"math"
 	"math/big"
 	"unicode"
@@ -330,50 +329,6 @@ func makeComplex(real, imag constant.Value) constant.Value {
 	return constant.BinaryOp(constant.ToFloat(real), token.ADD, constant.MakeImag(constant.ToFloat(imag)))
 }
 
-// For matching historical "constant OP overflow" error messages.
-// TODO(mdempsky): Replace with error messages like go/types uses.
-var overflowNames = [...]string{
-	ir.OADD:    "addition",
-	ir.OSUB:    "subtraction",
-	ir.OMUL:    "multiplication",
-	ir.OLSH:    "shift",
-	ir.OXOR:    "bitwise XOR",
-	ir.OBITNOT: "bitwise complement",
-}
-
-// OrigConst returns an OLITERAL with orig n and value v.
-func OrigConst(n ir.Node, v constant.Value) ir.Node {
-	lno := ir.SetPos(n)
-	v = ConvertVal(v, n.Type(), false)
-	base.Pos = lno
-
-	switch v.Kind() {
-	case constant.Int:
-		if constant.BitLen(v) <= ir.ConstPrec {
-			break
-		}
-		fallthrough
-	case constant.Unknown:
-		what := overflowNames[n.Op()]
-		if what == "" {
-			base.Fatalf("unexpected overflow: %v", n.Op())
-		}
-		base.ErrorfAt(n.Pos(), errors.NumericOverflow, "constant %v overflow", what)
-		n.SetType(nil)
-		return n
-	}
-
-	return ir.NewConstExpr(v, n)
-}
-
-func OrigBool(n ir.Node, v bool) ir.Node {
-	return OrigConst(n, constant.MakeBool(v))
-}
-
-func OrigInt(n ir.Node, v int64) ir.Node {
-	return OrigConst(n, constant.MakeInt64(v))
-}
-
 // DefaultLit on both nodes simultaneously;
 // if they're both ideal going in they better
 // get the same type going out.

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

@@ -274,7 +274,7 @@ func walkLenCap(n *ir.UnaryExpr, init *ir.Nodes) ir.Node {
 	}
 	if t.IsArray() {
 		safeExpr(n.X, init)
-		con := typecheck.OrigInt(n, t.NumElem())
+		con := ir.NewConstExpr(constant.MakeInt64(t.NumElem()), n)
 		con.SetTypecheck(1)
 		return con
 	}