Pass sourceFile to getChildren in getTokenAtPositionWorker (#25505) (#25538)
Pass sourceFile to getChildren in getTokenAtPositionWorker (#25505) (#25538)

For performance reasons, we should always pass sourceFile to getChildren
if available.
weswigham/TypeScript,kpreisser/TypeScript,donaldpipowitch/TypeScript,RyanCavanaugh/TypeScript,SaschaNaz/TypeScript,microsoft/TypeScript,nojvek/TypeScript,nojvek/TypeScript,basarat/TypeScript,kpreisser/TypeScript,weswigham/TypeScript,basarat/TypeScript,nojvek/TypeScript,nojvek/TypeScript,minestarks/TypeScript,SaschaNaz/TypeScript,basarat/TypeScript,donaldpipowitch/TypeScript,weswigham/TypeScript,alexeagle/TypeScript,basarat/TypeScript,microsoft/TypeScript,minestarks/TypeScript,alexeagle/TypeScript,kitsonk/TypeScript,kitsonk/TypeScript,donaldpipowitch/TypeScript,kpreisser/TypeScript,kitsonk/TypeScript,microsoft/TypeScript,Microsoft/TypeScript,RyanCavanaugh/TypeScript,minestarks/TypeScript,RyanCavanaugh/TypeScript,SaschaNaz/TypeScript,Microsoft/TypeScript,alexeagle/TypeScript,donaldpipowitch/TypeScript,SaschaNaz/TypeScript,Microsoft/TypeScript