nix: sourcehut build service manifests

nix: Development environment

Works with dependencies provided by Binary Builder, but needs to be
extended to build dependencies from source.

nix: Patch pre-built binary dependencies from BB

nix: Alternative README for fork

mark julia.write_barrier readonly on argument (#39742)

🤖 Bump the Pkg stdlib from 252e8950 to 9f7eaa36 (#42249)

Co-authored-by: Dilum Aluthge <dilum@aluthge.com>

🤖 Bump the Statistics stdlib from 54f9b0d to 74897fe (#42250)

Co-authored-by: Dilum Aluthge <dilum@aluthge.com>

lowering: copy expand-if optimization to expand-while (#42194)

Co-authored-by: Simeon Schaub <simeondavidschaub99@gmail.com>

[LLVM][PM] Make LowerSIMDLoop NewPM compatible (#40884)

* [LLVM][PM] Make LowerSIMDLoop NewPM compatible
* [LLVM][PM] Make DemoteFloat16 NewPM compatible
* [LLVM][PM] Make MulAdd NewPM compatible
* [LLVM][PM] Make RemoveNI NewPM compatible

Clarify `mkpath` docstring (#42160)

Co-authored-by: Curtis Vogt <curtis.vogt@gmail.com>

Co-authored-by: Curtis Vogt <curtis.vogt@gmail.com>

Merge pull request #42237 from JuliaLang/vc/rm_patch

[LLVM] Remove patch that is part of LLVM 13-rc3

Merge pull request #42172 from JuliaLang/jn/42168

fix collect on stateful iterators

precompile methods marked ccallable (#42153)

fix #42220: macro hygiene with unary `::` (#42221)

fix collect on stateful iterators

Generalization of #41919
Fixes #42168

bootstrapping: optimize compiler during warmup phase

inference: remove code that relies upon inferring the output type

Recursing into inference may be unreliable during inference.

test: make errorshow test more robust

Move `SHA` to be an external stdlib (#41370)

For the past few years, we have had `SHA` as a vendored copy, however
improvements have been made both to the vendored copy here in base as
well as to the registered copy living within `JuliaCrypto`.  This
eliminates the vendored copy and sets `SHA` up as an external stdlib
just like `Pkg`, `Tar`, and all of their friends, as well as merges the
improvements made to both into the external repository.

Merge pull request #42238 from JuliaLang/vc/distributed_rr

[Distributed] make nextproc use atomic operations