checker: allow a[i] for shared arrays outside unsafe (#8292)

vlib/v/checker/checker.v

@@ -4940,7 +4940,7 @@ pub fn (mut c Checker) index_expr(mut node ast.IndexExpr) table.Type {
 			if node.left.obj is ast.Var {
 				v := node.left.obj as ast.Var
 				// `mut param []T` function parameter
-				is_ok = v.is_mut && v.is_arg && !typ.deref().is_ptr()
+				is_ok = ((v.is_mut && v.is_arg) || v.share == .shared_t) && !typ.deref().is_ptr()
 			}
 		}
 		if !is_ok && !c.pref.translated {

vlib/v/tests/shared_array_test.v

@@ -19,19 +19,14 @@ fn test_shared_array() {
 	go incr(shared foo, 1)
 	for _ in 0 .. 50000 {
 		lock foo {
-			unsafe {
-				foo[0] -= 2
-				foo[1] += 3
-			}
+			foo[0] -= 2
+			foo[1] += 3
 		}
 	}
 	mut finished_threads := 0
 	for {
 		rlock foo {
-			finished_threads = unsafe {
-				foo[2]
-			}
-
+			finished_threads = foo[2]
 		}
 		if finished_threads == 4 {
 			break
@@ -39,14 +34,8 @@ fn test_shared_array() {
 		time.sleep_ms(100)
 	}
 	rlock foo {
-		f0 := unsafe {
-			foo[0]
-		}
-
-		f1 := unsafe {
-			foo[1]
-		}
-
+		f0 := foo[0]
+		f1 := foo[1]
 		assert f0 == 100010
 		assert f1 == 350020
 	}

vlib/v/tests/shared_map_test.v

@@ -12,9 +12,7 @@ fn incr(shared foo map[string]int, key string, sem sync.Semaphore) {
 fn test_shared_array() {
 	shared foo := &{'p': 10, 'q': 0}
 	lock foo {
-		unsafe {
-			foo['q'] = 20
-		}
+		foo['q'] = 20
 	}
 	sem := sync.new_semaphore()
 	go incr(shared foo, 'p', sem)
@@ -23,18 +21,16 @@ fn test_shared_array() {
 	go incr(shared foo, 'q', sem)
 	for _ in 0 .. 50000 {
 		lock foo {
-			unsafe {
-				foo['p'] -= 2
-				foo['q'] += 3
-			}
+			foo['p'] -= 2
+			foo['q'] += 3
 		}
 	}
 	for _ in 0..4 {
 		sem.wait()
 	}
 	rlock foo {
-		fp := unsafe { foo['p'] }
-		fq := unsafe { foo['q'] }
+		fp := foo['p']
+		fq := foo['q']
 		assert fp == 100010
 		assert fq == 350020
 	}