cmd/gc: fix spurious "bad negated constant" for complex constants.

Fixes #7648.

LGTM=r, remyoudompheng
R=golang-codereviews, r, remyoudompheng, jscrockett01
CC=golang-codereviews
https://golang.org/cl/80560045

src/cmd/gc/go.y

@@ -2140,6 +2140,10 @@ hidden_literal:
 		case CTFLT:
 			mpnegflt($$->val.u.fval);
 			break;
+		case CTCPLX:
+			mpnegflt(&$$->val.u.cval->real);
+			mpnegflt(&$$->val.u.cval->imag);
+			break;
 		default:
 			yyerror("bad negated constant");
 		}

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 2068 of yacc.c  */
 #line 28 "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;
 
-

test/fixedbugs/issue7648.dir/a.go

+// Copyright 2014 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 a
+
+const (
+	sinPi4 = 0.70710678118654752440084436210484903928483593768847
+	A = complex(sinPi4, -sinPi4)
+)
+

test/fixedbugs/issue7648.dir/b.go

+// Copyright 2014 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 b
+
+import "a"
+
+func f() {
+	println(a.A)
+}

test/fixedbugs/issue7648.go

+// compiledir
+
+// Copyright 2014 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.
+
+// Issue 7648: spurious "bad negated constant" for complex constants.
+
+package ignored