Add missing `f1_keywords` and `helpviewer_keywords` in "Compiler errors C7500 through C7999"

[Rageking8]

Add missing f1_keywords and helpviewer_keywords for errors introduced in commits https://github.com/MicrosoftDocs/cpp-docs/commit/82a27885175edb23e820741cf9750317c0ca2077 and https://github.com/MicrosoftDocs/cpp-docs/commit/5e13c40626cc4dc8a56fd842a2f9e1b5f6c62ff8. No other errors seem to be missing or extraneous.