tests: split unsafe.v to vlib/v/tests/unsafe_test.v and a checker output .vv&.out test

vlib/v/checker/tests/pointer_arithmetic_should_be_checked.out

@@ -0,0 +1,34 @@
+vlib/v/checker/tests/pointer_arithmetic_should_be_checked.v:4:6: error: pointer arithmetic is only allowed in `unsafe` blocks
+    2 |     v := 5
+    3 |     mut p := &v
+    4 |     p++
+      |      ~~
+    5 |     p += 2
+    6 |     _ := v
+vlib/v/checker/tests/pointer_arithmetic_should_be_checked.v:5:7: error: pointer arithmetic is only allowed in `unsafe` blocks
+    3 |     mut p := &v
+    4 |     p++
+    5 |     p += 2
+      |       ~~
+    6 |     _ := v
+    7 | }
+vlib/v/checker/tests/pointer_arithmetic_should_be_checked.v:11:14: error: pointer arithmetic is only allowed in `unsafe` blocks
+    9 | fn test_ptr_infix() {
+   10 |     v := 4
+   11 |     mut q := &v - 1
+      |              ^
+   12 |     q = q + 3
+   13 |     _ := q
+vlib/v/checker/tests/pointer_arithmetic_should_be_checked.v:12:9: error: pointer arithmetic is only allowed in `unsafe` blocks
+   10 |     v := 4
+   11 |     mut q := &v - 1
+   12 |     q = q + 3
+      |         ^
+   13 |     _ := q
+   14 |     _ := v
+vlib/v/checker/tests/pointer_arithmetic_should_be_checked.v:24:7: error: method `S1.f` must be called from an `unsafe` block
+   22 | fn test_funcs() {
+   23 |     s := S1{}
+   24 |     s.f()
+      |       ~~~
+   25 | }

vlib/v/tests/unsafe.out

@@ -1,34 +0,0 @@
-unsafe.v:4:6: warning: pointer arithmetic is only allowed in `unsafe` blocks
-    2 |     v := 5
-    3 |     mut p := &v
-    4 |     p++
-      |      ~~
-    5 |     p += 2
-    6 |     _ := v
-unsafe.v:5:7: warning: pointer arithmetic is only allowed in `unsafe` blocks
-    3 |     mut p := &v
-    4 |     p++
-    5 |     p += 2
-      |       ~~
-    6 |     _ := v
-    7 | }
-unsafe.v:11:14: warning: pointer arithmetic is only allowed in `unsafe` blocks
-    9 | fn test_ptr_infix() {
-   10 |     v := 4
-   11 |     mut q := &v - 1
-      |              ^
-   12 |     q = q + 3
-   13 |     _ := q
-unsafe.v:12:9: warning: pointer arithmetic is only allowed in `unsafe` blocks
-   10 |     v := 4
-   11 |     mut q := &v - 1
-   12 |     q = q + 3
-      |         ^
-   13 |     _ := q
-   14 |     _ := v
-unsafe.v:24:7: warning: method `S1.f` must be called from an `unsafe` block
-   22 | fn test_funcs() {
-   23 |     s := S1{}
-   24 |     s.f()
-      |       ~~~
-   25 | }

vlib/v/tests/unsafe_test.v

@@ -0,0 +1,31 @@
+fn test_ptr_assign() {
+    v := [int(5), 6, 77, 1]
+    mut p := &v[0]
+    unsafe { (*p)++ }
+    unsafe { p++ } // p now points to v[1]
+    unsafe { (*p) += 2 }
+    unsafe { p += 2 } // p now points to v[3]
+    unsafe { *p = 31 }
+	assert v[0] == 6
+	assert v[1] == 8
+	assert v[2] == 77
+	assert v[3] == 31
+}
+
+fn test_ptr_infix() {
+    v := 4
+    mut q := unsafe{ &v - 1 }
+    q = unsafe {q + 3}
+    _ := q
+    _ := v
+}
+
+struct S1 {}
+
+[unsafe_fn]
+fn (s S1) f(){}
+
+fn test_funcs() {
+    s := S1{}
+    unsafe { s.f() }
+}