tests: move rlock and shared array tests from `builtin` to `sync`

vlib/builtin/array_test.v

@@ -884,45 +884,6 @@ fn test_direct_modification() {
 	assert foo[2] == 3
 }
 
-fn test_shared_modification() {
-	shared foo := &[2, 0, 5]
-	lock foo {
-		unsafe {
-			foo[1] = 3
-			foo[0] *= 7
-			foo[1]--
-			foo[2] -= 2
-		}
-	}
-	rlock foo {
-		unsafe {
-			assert foo[0] == 14
-			assert foo[1] == 2
-			assert foo[2] == 3
-		}
-	}
-}
-
-[direct_array_access]
-fn test_shared_direct_modification() {
-	shared foo := &[2, 0, 5]
-	lock foo {
-		unsafe {
-			foo[1] = 3
-			foo[0] *= 7
-			foo[1]--
-			foo[2] -= 2
-		}
-	}
-	rlock foo {
-		unsafe {
-			assert foo[0] == 14
-			assert foo[1] == 2
-			assert foo[2] == 3
-		}
-	}
-}
-
 fn test_bools() {
 	println('test b')
 	mut a := [true, false]

vlib/sync/array_rlock_test.v

@@ -0,0 +1,38 @@
+fn test_shared_modification() {
+	shared foo := &[2, 0, 5]
+	lock foo {
+		unsafe {
+			foo[1] = 3
+			foo[0] *= 7
+			foo[1]--
+			foo[2] -= 2
+		}
+	}
+	rlock foo {
+		unsafe {
+			assert foo[0] == 14
+			assert foo[1] == 2
+			assert foo[2] == 3
+		}
+	}
+}
+
+[direct_array_access]
+fn test_shared_direct_modification() {
+	shared foo := &[2, 0, 5]
+	lock foo {
+		unsafe {
+			foo[1] = 3
+			foo[0] *= 7
+			foo[1]--
+			foo[2] -= 2
+		}
+	}
+	rlock foo {
+		unsafe {
+			assert foo[0] == 14
+			assert foo[1] == 2
+			assert foo[2] == 3
+		}
+	}
+}