internal: support std@dev.fuzz

It is now possible to fetch std@dev.fuzz and view /std@dev.fuzz on the
frontend.

For golang/go#46910

Change-Id: I2fd7259840ba32ff35ca323d07412988e533ffba
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/330413
Trust: Julie Qiu <julie@golang.org>
Run-TryBot: Julie Qiu <julie@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/internal/stdlib/testdata/dev.fuzz/src/errors/errors.go b/internal/stdlib/testdata/dev.fuzz/src/errors/errors.go
new file mode 100644
index 00000000..b8a46921
--- /dev/null
+++ b/internal/stdlib/testdata/dev.fuzz/src/errors/errors.go
@@ -0,0 +1,20 @@
+// Copyright 2011 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.
+
+// Package errors implements functions to manipulate errors.
+package errors
+
+// New returns an error that formats as the given text.
+func New(text string) error {
+	return &errorString{text}
+}
+
+// errorString is a trivial implementation of error.
+type errorString struct {
+	s string
+}
+
+func (e *errorString) Error() string {
+	return e.s
+}