cmd/gc: allow x[i:j:k] (and x[:j:k]) into the release

R=ken2
CC=golang-dev
https://golang.org/cl/13512053

src/cmd/gc/go.y

@@ -23,8 +23,6 @@
 #include <libc.h>
 #include "go.h"
 
-static int isrelease = -1;
-
 static void fixlbrace(int);
 %}
 %union	{
@@ -957,13 +955,6 @@ pexpr_no_paren:
 	}
 |	pexpr '[' oexpr ':' oexpr ':' oexpr ']'
 	{
-		// Make sure we don't accidentally release this experimental feature.
-		// http://golang.org/s/go12slice.
-		if(isrelease < 0)
-			isrelease = strstr(getgoversion(), "release") != nil;
-		if(isrelease)
-			yyerror("3-index slice not available in release");
-
 		if($5 == N)
 			yyerror("middle index required in 3-index slice");
 		if($7 == N)

src/cmd/gc/y.tab.h

-/* A Bison parser, made by GNU Bison 2.5.  */
+/* A Bison parser, made by GNU Bison 2.3.  */
 
-/* Bison interface for Yacc-like parsers in C
-   
-      Copyright (C) 1984, 1989-1990, 2000-2011 Free Software Foundation, Inc.
-   
-   This program is free software: you can redistribute it and/or modify
+/* Skeleton interface for Bison's Yacc-like parsers in C
+
+   Copyright (C) 1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006
+   Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation, either version 3 of the License, or
-   (at your option) any later version.
-   
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
-   
+
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
 
 /* As a special exception, you may create a larger work that contains
    part or all of the Bison parser skeleton and distribute that work
@@ -26,11 +29,10 @@
    special exception, which will cause the skeleton and the resulting
    Bison output files to be licensed under the GNU General Public
    License without this special exception.
-   
+
    This special exception was added by the Free Software Foundation in
    version 2.2 of Bison.  */
 
-
 /* Tokens.  */
 #ifndef YYTOKENTYPE
 # define YYTOKENTYPE
@@ -144,28 +146,22 @@
 
 #if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
 typedef union YYSTYPE
+#line 28 "go.y"
 {
-
-/* Line 2068 of yacc.c  */
-#line 30 "go.y"
-
 	Node*		node;
 	NodeList*		list;
 	Type*		type;
 	Sym*		sym;
 	struct	Val	val;
 	int		i;
-
-
-
-/* Line 2068 of yacc.c  */
-#line 163 "y.tab.h"
-} YYSTYPE;
-# define YYSTYPE_IS_TRIVIAL 1
+}
+/* Line 1529 of yacc.c.  */
+#line 160 "y.tab.h"
+	YYSTYPE;
 # define yystype YYSTYPE /* obsolescent; will be withdrawn */
 # define YYSTYPE_IS_DECLARED 1
+# define YYSTYPE_IS_TRIVIAL 1
 #endif
 
 extern YYSTYPE yylval;
 
-