Require been ignord for emitDecoratorMetadata if module is unused and name is lowercase #4239

import {db} from './db'
console.log('Hello Dexter Morgan');

console.log('Hello Dexter Morgan');

import {db} from './db';

function someDecorator(target) {
    return target;
}

@someDecorator
class MyClass {
    db: db;

    constructor(db: db) {
        this.db = db;
        this.db.doSomething();
    }
}

export {MyClass};

var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
    switch (arguments.length) {
        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, desc);
    }
};
var __metadata = (this && this.__metadata) || function (k, v) {
    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
};
function someDecorator(target) {
    return target;
}
var MyClass = (function () {
    function MyClass(db) {
        this.db = db;
        this.db.doSomething();
    }
    MyClass = __decorate([
        someDecorator, 
        __metadata('design:paramtypes', [db_1.db]) // db_1 is not defined
    ], MyClass);
    return MyClass;
})();
exports.MyClass = MyClass;

import {db as Database} from './db';

function someDecorator(target) {
    return target;
}

@someDecorator
class MyClass {
    db: Database;

    constructor(db: Database) {
        this.db = db;
        this.db.doSomething();
    }

}

export {MyClass}