gc: remove type elision in struct literals

R=ken2
CC=golang-dev
https://golang.org/cl/5437136

src/cmd/gc/typecheck.c

@@ -2183,7 +2183,7 @@ typecheckcomplit(Node **np)
 				s = f->sym;
 				fielddup(newname(s), hash, nhash);
 				r = l->right;
-				pushtype(r, f->type);
+				// No pushtype allowed here.  Tried and rejected.
 				typecheck(&r, Erv);
 				l->right = assignconv(r, f->type, "field value");
 			}

test/complit.go

@@ -58,7 +58,7 @@ func main() {
 	var tp *T
 	tp = &T{0, 7.2, "hi", &t}
 
-	tl := &T{i: 0, next: {i: 1, next: {i: 2, next: {i: 3, next: {i: 4}}}}}
+	tl := &T{i: 0, next: &T{i: 1, next: &T{i: 2, next: &T{i: 3, next: &T{i: 4}}}}}
 	teq(tl, 5)
 
 	a1 := []int{1, 2, 3}

test/complit1.go

@@ -34,6 +34,6 @@ type T struct {
 
 var (
 	_ = &T{0, 0, "", nil}               // ok
-	_ = &T{i: 0, f: 0, s: "", next: {}} // ok
+	_ = &T{i: 0, f: 0, s: "", next: {}} // ERROR "missing type in composite literal"
 	_ = &T{0, 0, "", {}}                // ERROR "missing type in composite literal"
 )