Auto merge of #50611 - alexcrichton:rollup, r=alexcrichton

Rollup of 18 pull requests

Successful merges:

 - #49423 (Extend tests for RFC1598 (GAT))
 - #50010 (Give SliceIndex impls a test suite of girth befitting the implementation (and fix a UTF8 boundary check))
 - #50447 (Fix update-references for tests within subdirectories.)
 - #50514 (Pull in a wasm fix from LLVM upstream)
 - #50524 (Make DepGraph::previous_work_products immutable)
 - #50532 (Don't use Lock for heavily accessed CrateMetadata::cnum_map.)
 - #50538 ( Make CrateNum allocation more thread-safe. )
 - #50564 (Inline `Span` methods.)
 - #50565 (Use SmallVec for DepNodeIndex within dep_graph.)
 - #50569 (Allow for specifying a linker plugin for cross-language LTO)
 - #50572 (Clarify in the docs that `mul_add` is not always faster.)
 - #50574 (add fn `into_inner(self) -> (Idx, Idx)` to RangeInclusive (#49022))
 - #50575 (std: Avoid `ptr::copy` if unnecessary in `vec::Drain`)
 - #50588 (Move "See also" disambiguation links for primitive types to top)
 - #50590 (Fix tuple struct field spans)
 - #50591 (Restore RawVec::reserve* documentation)
 - #50598 (Remove unnecessary mutable borrow and resizing in DepGraph::serialize)
 - #50606 (Retry when downloading the Docker cache.)

Failed merges:

 - #50161 (added missing implementation hint)
 - #50558 (Remove all reference to DepGraph::work_products)

0 files changed, 0 insertions, 0 deletions