llvm-project

fdb11c1b - [libc++] Disallow specializing `common_reference` (#141465)

[libc++] Disallow specializing `common_reference` (#141465) `common_reference` isn't an exception for [meta.rqmts]/4, so it's better to disallow users to specialize it. `indirectly_readable.compile.pass.cpp` was a bit problematic. It attempted to opt-out common reference type in some wrong ways. Also, the standard effectively forbids opting-out common reference type for `T&` and `T&&`. This patch removes and adjusts some problematic cases. --------- Co-authored-by: Nikolas Klauser <nikolasklauser@berlin.de>