Fix the up-to-date-ness checks of sucessive `gulp` invocations (#29088)
Fix the up-to-date-ness checks of sucessive `gulp` invocations (#29088)


SaschaNaz/TypeScript,RyanCavanaugh/TypeScript,weswigham/TypeScript,SaschaNaz/TypeScript,microsoft/TypeScript,alexeagle/TypeScript,RyanCavanaugh/TypeScript,nojvek/TypeScript,alexeagle/TypeScript,Microsoft/TypeScript,minestarks/TypeScript,kpreisser/TypeScript,minestarks/TypeScript,weswigham/TypeScript,kitsonk/TypeScript,SaschaNaz/TypeScript,nojvek/TypeScript,weswigham/TypeScript,RyanCavanaugh/TypeScript,alexeagle/TypeScript,kitsonk/TypeScript,SaschaNaz/TypeScript,microsoft/TypeScript,Microsoft/TypeScript,nojvek/TypeScript,kitsonk/TypeScript,minestarks/TypeScript,nojvek/TypeScript,microsoft/TypeScript,Microsoft/TypeScript,kpreisser/TypeScript,kpreisser/TypeScript