Auto merge of #71721 - tmandry:rollup-e27pxex, r=tmandry

Rollup of 8 pull requests

Successful merges:

 - #71148 (Vec drop and truncate: drop using raw slice *mut [T])
 - #71465 (Add a convenience method on `TyCtxt` for checking for thread locals)
 - #71567 (Handle build completion message from Cargo)
 - #71590 (MIR dump: print pointers consistently with Miri output)
 - #71682 (Bump pulldown-cmark)
 - #71688 (Allow `Downcast` projections unconditionally in const-checking)
 - #71691 (Allow `Unreachable` terminators unconditionally in const-checking)
 - #71719 (Update backtrace-sys)

Failed merges:

r? @ghost