gc: allow complex types to be receiver types

Fixes #1716.

R=golang-dev, rsc1, rsc
CC=golang-dev
https://golang.org/cl/4439068

src/cmd/gc/align.c

@@ -468,7 +468,7 @@ typeinit(void)
 			okforadd[i] = 1;
 			okforarith[i] = 1;
 			okforconst[i] = 1;
-//			issimple[i] = 1;
+			issimple[i] = 1;
 		}
 	}
 

src/cmd/gc/subr.c

@@ -488,7 +488,7 @@ algtype(Type *t)
 {
 	int a;
 
-	if(issimple[t->etype] || isptr[t->etype] || iscomplex[t->etype] ||
+	if(issimple[t->etype] || isptr[t->etype] ||
 		t->etype == TCHAN || t->etype == TFUNC || t->etype == TMAP) {
 		if(t->width == widthptr)
 			a = AMEMWORD;

test/fixedbugs/bug334.go

@@ -0,0 +1,31 @@
+// $G $D/$F.go || echo BUG: bug334
+
+// 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.
+
+// Issue 1716
+
+package main
+
+type (
+	cplx64  complex64
+	cplx128 complex128
+)
+
+func (c cplx64) Foo()  {}
+func (c cplx128) Foo() {}
+
+func main() {
+	var c64 cplx128
+	var c128 cplx64
+	c64.Foo()
+	c128.Foo()
+}
+
+/*
+bug334.go:16: invalid receiver type cplx64
+bug334.go:17: invalid receiver type cplx128
+bug334.go:22: c64.Foo undefined (type cplx128 has no field or method Foo)
+bug334.go:23: c128.Foo undefined (type cplx64 has no field or method Foo)
+*/