Auto merge of #139949 - matthiaskrgr:rollup-pxc5tsx, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #138632 (Stabilize `cfg_boolean_literals`)
 - #139416 (unstable book; document `macro_metavar_expr_concat`)
 - #139782 (Consistent with treating Ctor Call as Struct in liveness analysis)
 - #139885 (document RUSTC_BOOTSTRAP, RUSTC_OVERRIDE_VERSION_STRING, and -Z allow-features in the unstable book)
 - #139904 (Explicitly annotate edition for `unpretty=expanded` and `unpretty=hir` tests)
 - #139932 (transmutability: Refactor tests for simplicity)
 - #139944 (Move eager translation to a method on Diag)
 - #139948 (git: ignore `60600a6fa403216bfd66e04f948b1822f6450af7` for blame purposes)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors