[$] Blocking straight-line speculation — eventually

The Spectre class of vulnerabilities was given that name because, it wasthought, these problems would haunt us for a long time. As the fourthanniversary of the disclosure of Meltdown andSpectre approaches, there is no reason to doubt the accuracy of thatname. One of the more recent Spectre variants goes by the name "straight-linespeculation"; it was first disclosed in June 2020, but fixes are stilltrying to find their way into the compilers and the kernel.