test: migrate remaining tests to run.go

* bug248, bug345, bug369, and bug429 were ported from bash commands to run scripts. bug369 remains disabled.
* bug395 is a test for issue 1909, which is still open. It is marked as skip now and will be usable with compile with run.go when issue 1909 is fixed.

Fixes #4139

Updates #1909

Change-Id: Ibb5fbfb5cf72ddc285829245318eeacd3fb5a636
Reviewed-on: https://go-review.googlesource.com/1774
Reviewed-by: Russ Cox <rsc@golang.org>

test/fixedbugs/bug369.dir/main.go

@@ -0,0 +1,54 @@
+// 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 main
+
+import (
+	"flag"
+	"os"
+	"runtime"
+	"testing"
+
+	fast "./fast"
+	slow "./slow"
+)
+
+var buf = make([]byte, 1048576)
+
+func BenchmarkFastNonASCII(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		fast.NonASCII(buf, 0)
+	}
+}
+
+func BenchmarkSlowNonASCII(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		slow.NonASCII(buf, 0)
+	}
+}
+
+func main() {
+	os.Args = []string{os.Args[0], "-test.benchtime=100ms"}
+	flag.Parse()
+
+	rslow := testing.Benchmark(BenchmarkSlowNonASCII)
+	rfast := testing.Benchmark(BenchmarkFastNonASCII)
+	tslow := rslow.NsPerOp()
+	tfast := rfast.NsPerOp()
+
+	// Optimization should be good for at least 2x, but be forgiving.
+	// On the ARM simulator we see closer to 1.5x.
+	speedup := float64(tslow) / float64(tfast)
+	want := 1.8
+	if runtime.GOARCH == "arm" {
+		want = 1.3
+	}
+	if speedup < want {
+		// TODO(rsc): doesn't work on linux-amd64 or darwin-amd64 builders, nor on
+		// a Lenovo x200 (linux-amd64) laptop.
+		// println("fast:", tfast, "slow:", tslow, "speedup:", speedup, "want:", want)
+		// println("not fast enough")
+		// os.Exit(1)
+	}
+}