Rollup merge of rust-lang#126368 - nnethercote:rm-more-unused-crate-deps, r=jackh726

Remove some unnecessary crate dependencies.

A follow-up to rust-lang#126063.

r? `@jackh726`

Author: matthiaskrgr

Cargo.lock

@@ -4205,7 +4205,6 @@ dependencies = [
  "rustc_middle",
  "rustc_span",
  "rustc_target",
- "rustc_type_ir",
  "smallvec",
  "tracing",
 ]

compiler/rustc_data_structures/Cargo.toml

@@ -12,7 +12,6 @@ elsa = "=1.7.1"
 ena = "0.14.3"
 indexmap = { version = "2.0.0" }
 jobserver_crate = { version = "0.1.28", package = "jobserver" }
-libc = "0.2"
 measureme = "11"
 rustc-hash = "1.1.0"
 rustc-rayon = { version = "0.5.0", optional = true }
@@ -41,6 +40,11 @@ features = [
     "Win32_System_Threading",
 ]
 
+[target.'cfg(unix)'.dependencies]
+# tidy-alphabetical-start
+libc = "0.2"
+# tidy-alphabetical-end
+
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 # tidy-alphabetical-start
 memmap2 = "0.2.1"

compiler/rustc_infer/Cargo.toml

@@ -18,7 +18,6 @@ rustc_macros = { path = "../rustc_macros" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
-rustc_type_ir = { path = "../rustc_type_ir" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 # tidy-alphabetical-end