I know this is a bit of a cop-out, but you could roll your own:
clear_cache <- function() {
vapply(dir(pattern = "\\.(aux)|(bbl)|(bcf)|(blg)|(lof)|(out)|(run\\.xml)|(toc)$"),
file.remove,
FALSE))
}
Then Ctrl+2, clear_cache() (or an abbreviation), Ctrl+Shift+K.