_textSpanToRange is not a function/object doesn't support property or method

[wiredprairie]

Steps to reproduce:

1. Using the Demo web page, select TypeScript.
2. Right click on a symbol such as GameOfLife and select Go to symbol.

In the console (or an alert box depending on the browser), the following crash will happen:

TypeError: this._textSpanToRange is not a function
    at t (https://microsoft.github.io/monaco-editor/node_modules/monaco-editor/min/vs/language/typescript/src/mode.js:7:12226)
    at https://microsoft.github.io/monaco-editor/node_modules/monaco-editor/min/vs/language/typescript/src/mode.js:7:12443
    at Array.forEach (native)
    at https://microsoft.github.io/monaco-editor/node_modules/monaco-editor/min/vs/language/typescript/src/mode.js:7:12416
    at Object.g [as _notify] (https://microsoft.github.io/monaco-editor/node_modules/monaco-editor/min/vs/editor/editor.main.js:33:4544)
    at Object.enter (https://microsoft.github.io/monaco-editor/node_modules/monaco-editor/min/vs/editor/editor.main.js:33:8122)
    at _run (https://microsoft.github.io/monaco-editor/node_modules/monaco-editor/min/vs/editor/editor.main.js:33:9950)
    at _completed (https://microsoft.github.io/monaco-editor/node_modules/monaco-editor/min/vs/editor/editor.main.js:33:9391)
    at Object.g [as _notify] (https://microsoft.github.io/monaco-editor/node_modules/monaco-editor/min/vs/editor/editor.main.js:33:4544)
    at Object.enter (https://microsoft.github.io/monaco-editor/node_modules/monaco-editor/min/vs/editor/editor.main.js:33:8122)

Locally, I'm using 0.5.1 of the editor, and this issue happens in Chrome, Edge, and IE. (I've not tested with FireFox).

[jrieken]

got fixed