I noticed that people occasionally forget that unlike CHECK:, directives CHECK and CHECK : are not reacted upon by FileCheck. Tests still pass, but they don't actually test anything.
So i grepped real quick and found these four missing colons, one of which (the one in Analysis/cfg-rich-constructors.cpp) is mine. All four are in clang; there aren't any missing colons in other projects in the monorepo.
I'm not entirely sure about the change OpenMP/sections_lastprivate_codegen.cpp: it seems that replacing CHECK: with CHECK is a common way of making FIXME tests, but there's no indication anywhere that this is a known issue. The test was added in D11619.