bugfix es2018 import()

Author: jogibear9988

src/nodes.ts

@@ -485,8 +485,10 @@ export class IfStatement {
 
 export class Import {
     readonly type: string;
-    constructor() {
+    readonly source: Literal;
+    constructor(source) {
         this.type = Syntax.Import;
+        this.source = source;
     }
 }
 

src/parser.ts

@@ -1282,7 +1282,18 @@ export class Parser {
     parseImportCall(): Node.Import {
         const node = this.createNode();
         this.expectKeyword('import');
-        return this.finalize(node, new Node.Import());
+        this.expect("(");
+
+        const source = this.parseAssignmentExpression();
+        if (!this.match(")") && this.config.tolerant) {
+            this.tolerateUnexpectedToken(this.nextToken());
+        } else {
+            this.expect(")");
+            if (this.match(";")) {
+                this.nextToken();
+            }
+        }
+        return this.finalize(node, new Node.Import(source));
     }
 
     parseLeftHandSideExpressionAllowCall(): Node.Expression {