native: fix return `a+b` infix construction (#12161)

vlib/v/gen/native/amd64.v

@@ -777,7 +777,6 @@ pub fn (mut g Gen) call_fn(node ast.CallExpr) {
 	if !n.contains('.') {
 		n = 'main.$n'
 	}
-	eprintln('call fn ($n)')
 	addr := g.fn_addr[n]
 	if addr == 0 {
 		// g.warning('fn addr of `$name` = 0')

vlib/v/gen/native/gen.v

@@ -468,8 +468,7 @@ fn (mut g Gen) stmt(node ast.Stmt) {
 					g.mov64(.rax, e0.val.int())
 				}
 				ast.InfixExpr {
-					// TODO
-					// verror('expr')
+					g.infix_expr(e0)
 				}
 				ast.CastExpr {
 					g.mov64(.rax, e0.expr.str().int())
@@ -482,7 +481,6 @@ fn (mut g Gen) stmt(node ast.Stmt) {
 				}
 				ast.Ident {
 					g.expr(e0)
-					eprintln('ident $e0.name')
 				}
 				else {
 					g.n_error('unknown return type $e0.type_name()')

vlib/v/gen/native/tests/sumcall.vv

@@ -10,10 +10,9 @@ fn sumcall2(a int, b int) int {
 fn main() {
 	r := sumcall (1,2)
 	assert r == 3
-/*
-	// XXX not yet working
+
 	s := sumcall2 (1,2)
-	assert r == 3
-*/
+	assert s == 3
+
 	exit(0)
 }