types2: use strings.Builder in infer.go

Permissible now because go1.17 is used for bootstrapping.

Change-Id: Ic97b0706190c3eb907da69003bc94448c90e5af7
Reviewed-on: https://go-review.googlesource.com/c/go/+/427556
Run-TryBot: Robert Griesemer <gri@google.com>
Run-TryBot: hopehook <hopehook@golangcn.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Auto-Submit: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@google.com>

diff --git a/src/cmd/compile/internal/types2/infer.go b/src/cmd/compile/internal/types2/infer.go
index 8425cd603409d9333502024d9b53ab9dbaaaae22..d88eef640ad675e9aa9da551ebf15dfa8bba1ae3 100644 (file)
--- a/src/cmd/compile/internal/types2/infer.go
+++ b/src/cmd/compile/internal/types2/infer.go
@@ -7,9 +7,9 @@
 package types2
 
 import (
-       "bytes"
        "cmd/compile/internal/syntax"
        "fmt"
+       "strings"
 )
 
 const useConstraintTypeInference = true
@@ -338,8 +338,7 @@ func typeParamsString(list []*TypeParam) string {
        }
 
        // general case (n > 2)
-       // Would like to use strings.Builder but it's not available in Go 1.4.
-       var b bytes.Buffer
+       var b strings.Builder
        for i, tname := range list[:n-1] {
                if i > 0 {
                        b.WriteString(", ")