cgen: fix pushing to an array of string pointers (fix #14156)

Author: spytheman

vlib/v/gen/c/infix.v

@@ -708,7 +708,8 @@ fn (mut g Gen) infix_expr_left_shift_op(node ast.InfixExpr) {
 				g.write(', _MOV(($elem_type_str[]){ ')
 			}
 			// if g.autofree
-			needs_clone := array_info.elem_type.idx() == ast.string_type_idx && !g.is_builtin_mod
+			needs_clone := !g.is_builtin_mod && array_info.elem_type.idx() == ast.string_type_idx
+				&& array_info.elem_type.nr_muls() == 0
 			if needs_clone {
 				g.write('string_clone(')
 			}

vlib/v/tests/str_array_of_reference_test.v

@@ -1,7 +1,18 @@
-fn test_str_array_of_reference() {
+fn test_creating_an_array_of_string_reference() {
 	names := ['John', 'Paul', 'George', 'Ringo']
 	a := unsafe { [&names[0], &names[1]] }
 	println(a[0])
 	println(a)
 	assert '$a' == "[&'John', &'Paul']"
+	assert typeof(a[0]).name == '&string'
+}
+
+fn test_pushing_to_an_array_of_string_references() {
+	mut a := []&string{}
+	v1 := 'abc'
+	v2 := 'def'
+	a << &v1
+	a << &v2
+	assert *(a[0]) == 'abc'
+	assert *(a[1]) == 'def'
 }