Rollup of 4 pull requests

Successful merges:

 - #69439 (resolve: `lifetimes.rs` -> `late/lifetimes.rs`)
 - #69473 (update llvm to silence gcc 9 warnings)
 - #69479 (clarify operator precedence)
 - #69480 (Clean up E0373 explanation)

Failed merges:

 - #69481 (use char instead of &str for single char patterns)
 - #69496 (use find(x) instead of filter(x).next())

r? @ghost

…c-morse

use find(x) instead of filter(x).next()

Rollup of 8 pull requests

Successful merges:

 - #60826 (Implement new gdb/lldb pretty-printers)
 - #69255 (Add more context to E0599 errors)
 - #69379 (Fail on multiple declarations of `main`.)
 - #69430 (librustc_typeck: remove loop that never actually loops)
 - #69449 (Do not ping PR reviewers in toolstate breakage)
 - #69491 (rustc_span: Add `Symbol::to_ident_string` for use in diagnostic messages)
 - #69495 (don't take redundant references to operands)
 - #69496 (use find(x) instead of filter(x).next())

Failed merges:

r? @ghost

Rollup of 9 pull requests

Successful merges:

 - #69379 (Fail on multiple declarations of `main`.)
 - #69430 (librustc_typeck: remove loop that never actually loops)
 - #69449 (Do not ping PR reviewers in toolstate breakage)
 - #69491 (rustc_span: Add `Symbol::to_ident_string` for use in diagnostic messages)
 - #69495 (don't take redundant references to operands)
 - #69496 (use find(x) instead of filter(x).next())
 - #69501 (note that find(f) is equivalent to filter(f).next() in the docs.)
 - #69527 (Ignore untracked paths when running `rustfmt` on repository.)
 - #69529 (don't use .into() to convert types into identical types.)

Failed merges:

r? @ghost