title: Unable to compile TypeScript when import reflect-metadata
body: <p>I have a script,</p>
  
  <pre><code>import 'reflect-metadata'
  
  const plane = {
    color: 'red'
  }
  
  Reflect.defineMetadata('note', 'hi there', plane)
  </code></pre>
  
  <p>I set tsconfig.json,</p>
  
  <pre><code>/* Experimental Options */
  "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
  "emitDecoratorMetadata": true, 
  </code></pre>
  
  <p>And run <code>npm install reflect-metadata</code></p>
  
  <p>Use <code>ts-node</code> to run run it but got an error,</p>
  
  <pre><code># ts-node demo.ts
  /usr/local/lib/node_modules/ts-node/src/index.ts:293
      return new TSError(diagnosticText, diagnosticCodes)
             ^
  TSError: ⨯ Unable to compile TypeScript:
  test.ts:7:9 - error TS2339: Property 'defineMetadata' does not exist on type 'typeof Reflect'.
  
  7 Reflect.defineMetadata('note', 'hi there', plane)
            ~~~~~~~~~~~~~~
  
      at createTSError (/usr/local/lib/node_modules/ts-node/src/index.ts:293:12)
      at reportTSError (/usr/local/lib/node_modules/ts-node/src/index.ts:297:19)
      at getOutput (/usr/local/lib/node_modules/ts-node/src/index.ts:399:34)
      at Object.compile (/usr/local/lib/node_modules/ts-node/src/index.ts:457:32)
      at Module.m._compile (/usr/local/lib/node_modules/ts-node/src/index.ts:536:43)
      at Module._extensions..js (internal/modules/cjs/loader.js:973:10)
      at Object.require.extensions.&lt;computed&gt; [as .ts] (/usr/local/lib/node_modules/ts-node/src/index.ts:539:12)
      at Module.load (internal/modules/cjs/loader.js:812:32)
      at Function.Module._load (internal/modules/cjs/loader.js:724:14)
      at Function.Module.runMain (internal/modules/cjs/loader.js:1025:10)
  </code></pre>
  
  <p>But I can use <code>tsc demo.ts</code> to build a demo.js and run it without an error.</p>