internal: remove pre-go1.12 conditionally compiled files

Change-Id: I496ad24654990341eae9508587e950abde05b540
Reviewed-on: https://go-review.googlesource.com/c/tools/+/404334
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Alan Donovan <adonovan@google.com>

internal/span/token.go

@@ -183,7 +183,7 @@ func (l *FileConverter) ToOffset(line, col int) (int, error) {
 		// at the end of the file, allowing for a trailing eol
 		return l.file.Size(), nil
 	}
-	pos := lineStart(l.file, line)
+	pos := l.file.LineStart(line)
 	if !pos.IsValid() {
 		return -1, fmt.Errorf("line is not in file")
 	}

internal/span/token111.go

@@ -1,40 +0,0 @@
-// Copyright 2019 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 !go1.12
-// +build !go1.12
-
-package span
-
-import (
-	"go/token"
-)
-
-// lineStart is the pre-Go 1.12 version of (*token.File).LineStart. For Go
-// versions <= 1.11, we borrow logic from the analysisutil package.
-// TODO(rstambler): Delete this file when we no longer support Go 1.11.
-func lineStart(f *token.File, line int) token.Pos {
-	// Use binary search to find the start offset of this line.
-
-	min := 0        // inclusive
-	max := f.Size() // exclusive
-	for {
-		offset := (min + max) / 2
-		pos := f.Pos(offset)
-		posn := f.Position(pos)
-		if posn.Line == line {
-			return pos - (token.Pos(posn.Column) - 1)
-		}
-
-		if min+1 >= max {
-			return token.NoPos
-		}
-
-		if posn.Line < line {
-			min = offset
-		} else {
-			max = offset
-		}
-	}
-}

internal/span/token112.go

@@ -1,17 +0,0 @@
-// Copyright 2019 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 go1.12
-// +build go1.12
-
-package span
-
-import (
-	"go/token"
-)
-
-// TODO(rstambler): Delete this file when we no longer support Go 1.11.
-func lineStart(f *token.File, line int) token.Pos {
-	return f.LineStart(line)
-}

internal/testenv/testenv.go

@@ -13,6 +13,7 @@ import (
 	"io/ioutil"
 	"os"
 	"runtime"
+	"runtime/debug"
 	"strings"
 	"sync"
 	"time"
@@ -32,10 +33,19 @@ type helperer interface {
 
 // packageMainIsDevel reports whether the module containing package main
 // is a development version (if module information is available).
-//
-// Builds in GOPATH mode and builds that lack module information are assumed to
-// be development versions.
-var packageMainIsDevel = func() bool { return true }
+func packageMainIsDevel() bool {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		// Most test binaries currently lack build info, but this should become more
+		// permissive once https://golang.org/issue/33976 is fixed.
+		return true
+	}
+
+	// Note: info.Main.Version describes the version of the module containing
+	// package main, not the version of “the main module”.
+	// See https://golang.org/issue/33975.
+	return info.Main.Version == "(devel)"
+}
 
 var checkGoGoroot struct {
 	once sync.Once

internal/testenv/testenv_112.go

@@ -1,28 +0,0 @@
-// Copyright 2019 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 go1.12
-// +build go1.12
-
-package testenv
-
-import "runtime/debug"
-
-func packageMainIsDevelModule() bool {
-	info, ok := debug.ReadBuildInfo()
-	if !ok {
-		// Most test binaries currently lack build info, but this should become more
-		// permissive once https://golang.org/issue/33976 is fixed.
-		return true
-	}
-
-	// Note: info.Main.Version describes the version of the module containing
-	// package main, not the version of “the main module”.
-	// See https://golang.org/issue/33975.
-	return info.Main.Version == "(devel)"
-}
-
-func init() {
-	packageMainIsDevel = packageMainIsDevelModule
-}