gc: bug325 / issue 1566

Fixes #1566.

R=ken2
CC=golang-dev
https://golang.org/cl/4259041

src/cmd/gc/subr.c

@@ -203,7 +203,6 @@ fatal(char *fmt, ...)
 
 	flusherrors();
 
-*(int*)0=0;
 	print("%L: internal compiler error: ", lineno);
 	va_start(arg, fmt);
 	vfprint(1, fmt, arg);

src/cmd/gc/typecheck.c

@@ -318,7 +318,7 @@ reswitch:
 			n->left = N;
 			goto ret;
 		}
-		if(!isptr[t->etype]) {
+		if(!isptr[t->etype] || (t->type != T && t->type->etype == TANY) /* unsafe.Pointer */) {
 			yyerror("invalid indirect of %+N", n->left);
 			goto error;
 		}

test/fixedbugs/bug325.go

+// errchk $G $D/$F.go
+
+// Copyright 2011 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 main
+
+import "unsafe"
+
+func main() {
+	var x unsafe.Pointer
+	println(*x) // ERROR "invalid indirect.*unsafe.Pointer"
+}