Pin memchr to 2.5.0 in the library rather than rustc_ast

The latest versions of `memchr` experience LTO-related issues when
compiling for windows-gnu [1], so needs to be pinned. The issue is
present in the standard library.

`memchr` has been pinned in `rustc_ast`, but since the workspace was
recently split, this pin no longer has any effect on library crates.

Resolve this by adding `memchr` as an _unused_ dependency in `std`,
pinned to 2.5. Additionally, remove the pin in `rustc_ast` to allow
non-library crates to upgrade to the latest version.

Link: rust-lang#127890 [1]

Author: tgross35

Cargo.lock

@@ -2186,9 +2186,9 @@ dependencies = [
 
 [[package]]
 name = "memchr"
-version = "2.5.0"
+version = "2.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
+checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
 
 [[package]]
 name = "memmap2"

compiler/rustc_ast/Cargo.toml

@@ -4,10 +4,9 @@ version = "0.0.0"
 edition = "2021"
 
 [dependencies]
-# 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 = "2.7.4"
 rustc_ast_ir = { path = "../rustc_ast_ir" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_index = { path = "../rustc_index" }

library/Cargo.lock

@@ -42,9 +42,12 @@ checksum = "5c6cb57a04249c6480766f7f7cef5467412af1490f8d1e243141daddada3264f"
 
 [[package]]
 name = "cc"
-version = "1.0.99"
+version = "1.1.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96c51067fd44124faa7f870b4b1c969379ad32b2ba805aa959430ceaa384f695"
+checksum = "57b6a275aa2903740dc87da01c62040406b8812552e97129a63ea8850a17c6e6"
+dependencies = [
+ "shlex",
+]
 
 [[package]]
 name = "cfg-if"
@@ -58,9 +61,9 @@ dependencies = [
 
 [[package]]
 name = "compiler_builtins"
-version = "0.1.121"
+version = "0.1.122"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce956e6dc07082ec481f0935a51e83b343f8ca51be560452c0ebf830d0bdf5a5"
+checksum = "94d9eb5c3e8b84831ea59a2948f0b9ffec898044c28337f28f52b0781d08c459"
 dependencies = [
  "cc",
  "rustc-std-workspace-core",
@@ -110,9 +113,9 @@ dependencies = [
 
 [[package]]
 name = "gimli"
-version = "0.28.1"
+version = "0.29.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4271d37baee1b8c7e4b708028c57d816cf9d2434acb33a549475f78c181f6253"
+checksum = "40ecd4077b5ae9fd2e9e169b102c6c330d0605168eb0e8bf79952b256dbefffd"
 dependencies = [
  "compiler_builtins",
  "rustc-std-workspace-alloc",
@@ -121,9 +124,9 @@ dependencies = [
 
 [[package]]
 name = "gimli"
-version = "0.29.0"
+version = "0.30.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "40ecd4077b5ae9fd2e9e169b102c6c330d0605168eb0e8bf79952b256dbefffd"
+checksum = "e2e1d97fbe9722ba9bbd0c97051c2956e726562b61f86a25a4360398a40edfc9"
 dependencies = [
  "compiler_builtins",
  "rustc-std-workspace-alloc",
@@ -186,9 +189,9 @@ dependencies = [
 
 [[package]]
 name = "object"
-version = "0.36.2"
+version = "0.36.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f203fa8daa7bb185f760ae12bd8e097f63d17041dcdcaf675ac54cdf863170e"
+checksum = "27b64972346851a39438c60b341ebc01bba47464ae329e55cf343eb93964efd9"
 dependencies = [
  "compiler_builtins",
  "memchr",
@@ -312,6 +315,12 @@ dependencies = [
  "std",
 ]
 
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
 [[package]]
 name = "std"
 version = "0.0.0"
@@ -326,6 +335,7 @@ dependencies = [
  "hashbrown",
  "hermit-abi",
  "libc",
+ "memchr",
  "miniz_oxide",
  "object",
  "panic_abort",
@@ -396,12 +406,12 @@ dependencies = [
 
 [[package]]
 name = "unwinding"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37a19a21a537f635c16c7576f22d0f2f7d63353c1337ad4ce0d8001c7952a25b"
+checksum = "dc55842d0db6329a669d55a623c674b02d677b16bfb2d24857d4089d41eba882"
 dependencies = [
  "compiler_builtins",
- "gimli 0.28.1",
+ "gimli 0.30.0",
  "rustc-std-workspace-core",
 ]
 
@@ -422,7 +432,7 @@ version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
 dependencies = [
- "windows-targets 0.52.5",
+ "windows-targets 0.52.6",
 ]
 
 [[package]]
@@ -431,9 +441,9 @@ version = "0.0.0"
 
 [[package]]
 name = "windows-targets"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f0713a46559409d202e70e28227288446bf7841d3211583a4b53e3f6d96e7eb"
+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
 dependencies = [
  "windows_aarch64_gnullvm",
  "windows_aarch64_msvc",
@@ -447,48 +457,48 @@ dependencies = [
 
 [[package]]
 name = "windows_aarch64_gnullvm"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7088eed71e8b8dda258ecc8bac5fb1153c5cffaf2578fc8ff5d61e23578d3263"
+checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
 
 [[package]]
 name = "windows_aarch64_msvc"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9985fd1504e250c615ca5f281c3f7a6da76213ebd5ccc9561496568a2752afb6"
+checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
 
 [[package]]
 name = "windows_i686_gnu"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "88ba073cf16d5372720ec942a8ccbf61626074c6d4dd2e745299726ce8b89670"
+checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
 
 [[package]]
 name = "windows_i686_gnullvm"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "87f4261229030a858f36b459e748ae97545d6f1ec60e5e0d6a3d32e0dc232ee9"
+checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
 
 [[package]]
 name = "windows_i686_msvc"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db3c2bf3d13d5b658be73463284eaf12830ac9a26a90c717b7f771dfe97487bf"
+checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
 
 [[package]]
 name = "windows_x86_64_gnu"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e4246f76bdeff09eb48875a0fd3e2af6aada79d409d33011886d3e1581517d9"
+checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
 
 [[package]]
 name = "windows_x86_64_gnullvm"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "852298e482cd67c356ddd9570386e2862b5673c85bd5f88df9ab6802b334c596"
+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
 
 [[package]]
 name = "windows_x86_64_msvc"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bec47e5bfd1bff0eeaf6d8b485cc1074891a197ab4225d504cb7a1ab88b02bf0"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"

library/std/Cargo.toml

@@ -23,6 +23,10 @@ unwind = { path = "../unwind" }
 hashbrown = { version = "0.14", default-features = false, features = [
     'rustc-dep-of-std',
 ] }
+# FIXME(#127890): `object` depends on `memchr`, but `memchr` > v2.5 causes
+# issues with LTO. This dependency is not used directly, but pin it here so
+# it is resolved 2.5. To be removed once rust-lang/rust#127890 is fixed.
+memchr = { version = "=2.5.0", default-features = false, features = ["rustc-dep-of-std"] }
 std_detect = { path = "../stdarch/crates/std_detect", default-features = false, features = [
     'rustc-dep-of-std',
 ] }