🐛 fix hasSideEffect false negative

Author: mysticatea

docs/api/ast-utils.md

@@ -363,6 +363,7 @@ The side effect means that it *may* modify a certain variable or object member.
 - `AssignmentExpression`
 - `AwaitExpression`
 - `CallExpression`
+- `ImportExpression`
 - `NewExpression`
 - `UnaryExpression` (`[operator = "delete"]`)
 - `UpdateExpression`

src/has-side-effect.js

@@ -83,6 +83,9 @@ const visitor = Object.freeze(
         FunctionExpression() {
             return false
         },
+        ImportExpression() {
+            return true
+        },
         MemberExpression(node, options, visitorKeys) {
             if (options.considerGetters) {
                 return true