Auto merge of #63700 - alexcrichton:update-backtrace, r=sfackler

Auto merge of #63700 - alexcrichton:update-backtrace, r=sfackler

std: Update `backtrace` crate dependency

This commit updates the `backtrace` crate from 0.3.34 to 0.3.35. The
[included set of changes][changes] for this update mostly includes some
gimli-related improvements (not relevant for the standard library) but
critically includes a fix for rust-lang/backtrace-rs#230. The standard
library will not aqcuire a session-local lock whenever a backtrace is
generated on Windows to allow external synchronization with the
`backtrace` crate itself, allowing `backtrace` to be safely used while
other threads may be panicking.

[changes]: https://github.com/rust-lang/backtrace-rs/compare/0.3.34...0.3.35