<valarray>: Cleanups and length checking for binary operations - #3911

<valarray>: Cleanups and length checking for binary operations#3911

Stephan T. Lavavej (StephanTLavavej) merged 8 commits into

microsoft:mainmicrosoft/STL:mainfrom

frederick-vs-ja:valarray-enhancementfrederick-vs-ja/STL:valarray-enhancementCopy head branch name to clipboard