cmd: vendor golang.org/x/tools/cmd/bisect

Vendoring for use with the internal/godebug test
and eventually the cmd/compile test as well.

Change-Id: I3f7151949cff584705cb32ba39bf5de5cd45c3f2
Reviewed-on: https://go-review.googlesource.com/c/go/+/493597
Reviewed-by: Ian Lance Taylor <[email protected]>
Run-TryBot: Russ Cox <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>

Author: rsc

src/cmd/tools/tools.go

@@ -0,0 +1,11 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build tools
+
+package tools
+
+// Arrange to vendor the bisect command for use
+// by the internal/godebug package test.
+import _ "golang.org/x/tools/cmd/bisect"