tests: [] fixes

vlib/v/checker/tests/inout/left_shift_err.vv

@@ -1,4 +1,4 @@
 fn main() {
-	l := []int
+	l := []int{}
 	l << 'test'
 }

vlib/v/fmt/fmt_keep_test.v

@@ -28,7 +28,7 @@ fn test_fmt() {
 	mut fmt_bench := benchmark.new_benchmark()
 	keep_input_files := os.walk_ext('$vroot/vlib/v/fmt/tests', '_keep.vv')
 	expected_input_files := os.walk_ext('$vroot/vlib/v/fmt/tests', '_expected.vv')
-	mut input_files := []string
+	mut input_files := []string{}
 	input_files << keep_input_files
 	input_files << expected_input_files
 	fmt_bench.set_total_expected_steps(input_files.len)

vlib/v/fmt/tests/type_ptr_keep.vv

@@ -1,13 +1,13 @@
 const (
 	x = &Test{}
-	y = []&Test
-	z = &[]&Test
+	y = []&Test{}
+	z = &[]&Test{}
 )
 
 fn test_type_ptr() {
 	_ := &Test{}
-	_ := []&Test
-	_ := &[]&Test
+	_ := []&Test{}
+	_ := &[]&Test{}
 }
 
 struct Test {