Remove broken TOML 1.1 "Unicode keys" feature

bench_test.go

@@ -79,8 +79,7 @@ func BenchmarkEncode(b *testing.B) {
 			// "next" version of TOML.
 			switch path {
 			case "valid/string/escape-esc.toml", "valid/datetime/no-seconds.toml",
-				"valid/string/hex-escape.toml", "valid/inline-table/newline.toml",
-				"valid/key/unicode.toml":
+				"valid/string/hex-escape.toml", "valid/inline-table/newline.toml":
 				return nil
 			}
 

lex.go

@@ -1265,23 +1265,6 @@ func isBinary(r rune) bool { return r == '0' || r == '1' }
 func isOctal(r rune) bool  { return r >= '0' && r <= '7' }
 func isHex(r rune) bool    { return (r >= '0' && r <= '9') || (r|0x20 >= 'a' && r|0x20 <= 'f') }
 func isBareKeyChar(r rune, tomlNext bool) bool {
-	if tomlNext {
-		return (r >= 'A' && r <= 'Z') ||
-			(r >= 'a' && r <= 'z') ||
-			(r >= '0' && r <= '9') ||
-			r == '_' || r == '-' ||
-			r == 0xb2 || r == 0xb3 || r == 0xb9 || (r >= 0xbc && r <= 0xbe) ||
-			(r >= 0xc0 && r <= 0xd6) || (r >= 0xd8 && r <= 0xf6) || (r >= 0xf8 && r <= 0x037d) ||
-			(r >= 0x037f && r <= 0x1fff) ||
-			(r >= 0x200c && r <= 0x200d) || (r >= 0x203f && r <= 0x2040) ||
-			(r >= 0x2070 && r <= 0x218f) || (r >= 0x2460 && r <= 0x24ff) ||
-			(r >= 0x2c00 && r <= 0x2fef) || (r >= 0x3001 && r <= 0xd7ff) ||
-			(r >= 0xf900 && r <= 0xfdcf) || (r >= 0xfdf0 && r <= 0xfffd) ||
-			(r >= 0x10000 && r <= 0xeffff)
-	}
-
-	return (r >= 'A' && r <= 'Z') ||
-		(r >= 'a' && r <= 'z') ||
-		(r >= '0' && r <= '9') ||
-		r == '_' || r == '-'
+	return (r >= 'A' && r <= 'Z') || (r >= 'a' && r <= 'z') ||
+		(r >= '0' && r <= '9') || r == '_' || r == '-'
 }

toml_test.go

@@ -263,8 +263,7 @@ func TestTomlNextFails(t *testing.T) {
 		"valid/string/escape-esc",
 		"valid/datetime/no-seconds",
 		"valid/string/hex-escape",
-		"valid/inline-table/newline",
-		"valid/key/unicode")
+		"valid/inline-table/newline")
 }
 
 func runTomlTest(t *testing.T, includeNext bool, wantFail ...string) {