Fix tests for older Go versions

Author: arp242

error.go

@@ -10,7 +10,7 @@ import (
 // For example invalid syntax, duplicate keys, etc.
 //
 // In addition to the error message itself, you can also print detailed location
-// information with context by using ErrorWithLocation():
+// information with context by using ErrorWithPosition():
 //
 //     toml: error: Key 'fruit' was already created and cannot be used as an array.
 //

error_test.go

@@ -121,7 +121,7 @@ func TestParseError(t *testing.T) {
 		fmt.Println("\x1b[1m━━━", path, strings.Repeat("━", 65-len(path)), "\x1b[0m")
 		fmt.Print(pErr.Error())
 		fmt.Println()
-		fmt.Println("─── ErrorWithLocation()", strings.Repeat("–", 47))
+		fmt.Println("─── ErrorWithPosition()", strings.Repeat("–", 47))
 		fmt.Print(pErr.ErrorWithPosition())
 		fmt.Println("─── ErrorWithUsage()", strings.Repeat("–", 50))
 		fmt.Print(pErr.ErrorWithUsage())

internal/toml-test/json.go

@@ -1,3 +1,6 @@
+//go:build go1.16
+// +build go1.16
+
 package tomltest
 
 import (

internal/toml-test/runner.go

@@ -1,5 +1,8 @@
 //go:generate ./gen-multi.py
 
+//go:build go1.16
+// +build go1.16
+
 package tomltest
 
 import (

internal/toml-test/toml.go

@@ -1,3 +1,6 @@
+//go:build go1.16
+// +build go1.16
+
 package tomltest
 
 import (