DNM: Try using memchr without inlining on windows

.github/workflows/ci.yml

@@ -607,10 +607,13 @@ jobs:
     strategy:
       matrix:
         include:
-          - name: dist-x86_64-linux
+          - name: x86_64-mingw
             env:
-              CODEGEN_BACKENDS: "llvm,cranelift"
-            os: ubuntu-20.04-16core-64gb
+              SCRIPT: make ci-mingw
+              RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-gnu --enable-profiler"
+              NO_DOWNLOAD_CI_LLVM: 1
+              CUSTOM_MINGW: 1
+            os: windows-2019-8core-32gb
     defaults:
       run:
         shell: "${{ contains(matrix.os, 'windows') && 'msys2 {0}' || 'bash' }}"

Cargo.lock

@@ -2372,9 +2372,8 @@ dependencies = [
 
 [[package]]
 name = "memchr"
-version = "2.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
+version = "2.6.0"
+source = "git+https://github.com/flip1995/memchr.git#f2e2936815bf211ece60a0251b53a617e1d678ac"
 dependencies = [
  "compiler_builtins",
  "rustc-std-workspace-core",

Cargo.toml

@@ -118,6 +118,7 @@ strip = true
 rustc-std-workspace-core = { path = 'library/rustc-std-workspace-core' }
 rustc-std-workspace-alloc = { path = 'library/rustc-std-workspace-alloc' }
 rustc-std-workspace-std = { path = 'library/rustc-std-workspace-std' }
+memchr = { git = "https://github.com/flip1995/memchr.git" }
 
 [patch."https://github.com/rust-lang/rust-clippy"]
 clippy_lints = { path = "src/tools/clippy/clippy_lints" }

compiler/rustc_ast/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2021"
 # FIXME: bumping memchr to 2.7.1 causes linker errors in MSVC thin-lto
 # tidy-alphabetical-start
 bitflags = "2.4.1"
-memchr = "=2.5.0"
+memchr = "2.6.0"
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_index = { path = "../rustc_index" }
 rustc_lexer = { path = "../rustc_lexer" }

src/ci/github-actions/ci.yml

@@ -755,13 +755,18 @@ jobs:
     strategy:
       matrix:
         include:
-          - &dist-x86_64-linux
-            name: dist-x86_64-linux
+          - &x86_64-mingw
+            name: x86_64-mingw
             env:
-              CODEGEN_BACKENDS: llvm,cranelift
-            <<: *job-linux-16c
-
-
+              SCRIPT: make ci-mingw
+              RUST_CONFIGURE_ARGS: >-
+                --build=x86_64-pc-windows-gnu
+                --enable-profiler
+              # We are intentionally allowing an old toolchain on this builder (and that's
+              # incompatible with LLVM downloads today).
+              NO_DOWNLOAD_CI_LLVM: 1
+              CUSTOM_MINGW: 1
+            <<: *job-windows-8c
   master:
     name: master
     runs-on: ubuntu-latest

src/tools/tidy/src/extdeps.rs

@@ -4,7 +4,10 @@ use std::fs;
 use std::path::Path;
 
 /// List of allowed sources for packages.
-const ALLOWED_SOURCES: &[&str] = &["\"registry+https://github.com/rust-lang/crates.io-index\""];
+const ALLOWED_SOURCES: &[&str] = &[
+    "\"registry+https://github.com/rust-lang/crates.io-index\"",
+    "\"git+https://github.com/flip1995/memchr.git#f2e2936815bf211ece60a0251b53a617e1d678ac\"",
+];
 
 /// Checks for external package sources. `root` is the path to the directory that contains the
 /// workspace `Cargo.toml`.