Crash when requesting infer parameter types from usage codefix

[sandersn]

The crash happens when a parameter is followed by a C-style comment in a JS file:

function call(callback /*oh no*/) {
  return callback(this)
}

Expected behavior:
Provide a codefix "Infer parameter types from usage".

Actual behavior:
Crash:

     Error: Debug Failure. False expression: Node must have a real position for this operation
      at NodeObject.assertHasRealPosition (src/services/services.ts:37:19)
      at NodeObject.getStart (src/services/services.ts:45:18)
      at processChildNode (src/services/formatting/formatting.ts:645:45)
      at processChildNodes (src/services/formatting/formatting.ts:757:44)
      at /home/nathansa/ts/src/services/formatting/formatting.ts:623:21
      at visitNodes (src/compiler/parser.ts:40:24)
      at Object.forEachChild (src/compiler/parser.ts:462:24)
      at processNode (src/services/formatting/formatting.ts:617:13)
      at formatSpanWorker (src/services/formatting/formatting.ts:415:13)
      at /home/nathansa/ts/src/services/formatting/formatting.ts:340:108
      at Object.getFormattingScanner (src/services/formatting/formattingScanner.ts:38:21)
      at Object.formatNodeGivenIndentation (src/services/formatting/formatting.ts:340:16)
      at getFormattedTextOfNode (src/services/textChanges.ts:819:40)
      at format (src/services/textChanges.ts:796:41)
      at computeNewText (src/services/textChanges.ts:799:19)
      at /home/nathansa/ts/src/services/textChanges.ts:769:72
      at Array.map (<anonymous>)
      at /home/nathansa/ts/src/services/textChanges.ts:768:48
      at Array.map (<anonymous>)
      at Object.getTextChangesFromChanges (src/services/textChanges.ts:758:59)
      at ChangeTracker.getChanges (src/services/textChanges.ts:726:43)
      at Function.ChangeTracker.with (src/services/textChanges.ts:225:28)
      at Object.getCodeActions (src/services/codefixes/inferFromUsage.ts:32:59)

Fourslash repro

/// <reference path='fourslash.ts' />

// @allowJs: true
// @checkJs: true
// @noEmit: true
// @noImplicitAny: true
// @Filename: important.js


////function coll(callback /*, name1, name2, ... */) {
////     return callback(this);
////};

verify.codeFix({
    description: "Infer parameter types from usage",
    index: 2,
    newFileContent:
`
/**
 * @param {(arg0: any) => void} callback
 */
function coll(callback /*, name1, name2, ... */) {
    return callback(this);
}
`,
});

[sandersn]

The emitter emits trailing comments of identifiers, meaning that the emitted comment was unintentionally:

/**
 * @param {(arg0: any) => void} callback /*, name1, name2, ... */
 */

github's syntax colouring should be good enough to show that the last line is a syntax error.