Carried: libc 0.2.190 breaks the iOS check through backtrace 0.3.76 #668

Dependency problem, carried per CONTRIBUTING (Problems that may be a dependency's).

Localize. The dependabot bump #665 (libc 0.2.189 → 0.2.190) fails only the iOS check (cargo check -p tcode-ios --target aarch64-apple-ios-sim). Reproduced locally on the branch.

Impact. The iOS build of Tcode cannot compile with libc 0.2.190. Desktop, Android, Web are unaffected.

Cause (confirmed in the dependency sources). libc 0.2.190 moves AF_SYS_CONTROL, SYSPROTO_EVENT, SYSPROTO_CONTROL and the _dyld_get_image_header / _dyld_get_image_vmaddr_slide declarations inside cfg(target_os = "macos") (src/unix/bsd/apple/mod.rs:3075 and :5047–5050 in 0.2.190; unconditional in 0.2.189). Two consumers still reference them on every Apple target:

• rustix 1.1.4 (src/net/types.rs:744, :1128–1131) — fixed in rustix 1.1.5, which gates them to macOS; the bump is applied in build(deps): bump the cargo-minor-and-patch group across 1 directory with 11 updates #665.
• backtrace 0.3.76 (src/symbolize/gimli/libs_macos.rs:46, :140), pulled in by gpui — no fixed release yet (0.3.76 is the latest; master still calls them unconditionally).

Carry. crates/platform/gpui-ios/Cargo.toml holds libc = ">=0.2, <0.2.190" with a comment naming this behaviour. Remove the hold when a backtrace release gates the _dyld_* calls to macOS (or gpui stops depending on backtrace on iOS). Acting on the upstream repositories is the maintainer's call.