use ++ everywhere

vlib/compiler/tests/defer_test.v

@@ -16,7 +16,7 @@ fn test_defer() {
 }
 
 fn set_num(i int, n mut Num) {
-	defer { n.val+=1 }
+	defer { n.val++ }
 	println("Hi")
 	if i < 5 {
 		return

vlib/compiler/tests/mut_test.v

@@ -41,7 +41,8 @@ fn test_mut_2() {
 	b.a[zero].v << 5
 
 	b.a[0].v[zero] = 3
-	b.a[0].v[b.a[zero].v[zero]] += 1b.a[0].v[b.a[0].v[zero]] += 1
+	b.a[0].v[b.a[zero].v[zero]]++
+	b.a[0].v[b.a[0].v[zero]]++
 
 	assert b.a[0].v.len == 5
 	assert b.a[0].v[0] == 3

vlib/compiler/tests/pointers_test.v

@@ -3,7 +3,7 @@ fn test_pointer_arithmetic() {
 	arr := [1,2,3,4]
 	unsafe {
 		mut parr := *int(arr.data)
-		parr += 1
+		parr++
 		assert 2 == *parr
 		parr++
 		assert 3 == *parr