build: Remove RUST_LIBC_UNSTABLE_LINUX_TIME_BITS64

Currently this isn't used for any testing, and there isn't really a time
when it would be useful to set this: it is always set by the libc in
practice. Thus, remove it.

Author: tgross35

build.rs

@@ -106,11 +106,6 @@ fn main() {
         // FIXME(musl): enable time64 api as well
         set_cfg("musl_v1_2_3");
     }
-    let linux_time_bits64 = env_flag("RUST_LIBC_UNSTABLE_LINUX_TIME_BITS64");
-    println!("cargo:rerun-if-env-changed=RUST_LIBC_UNSTABLE_LINUX_TIME_BITS64");
-    if linux_time_bits64 {
-        set_cfg("linux_time_bits64");
-    }
     println!("cargo:rerun-if-env-changed=RUST_LIBC_UNSTABLE_GNU_FILE_OFFSET_BITS");
     println!("cargo:rerun-if-env-changed=RUST_LIBC_UNSTABLE_GNU_TIME_BITS");
     if target_env == "gnu"

ci/verify-build.py

@@ -390,11 +390,6 @@ def test_target(cfg: Cfg, target: Target) -> TargetResult:
     run(cmd, env=env)
     run([*cmd, "--features=extra_traits"], env=env)
 
-    # Check with different env for 64-bit time_t
-    if target_os == "linux" and target_bits == "32":
-        # Equivalent of __USE_TIME_BITS64
-        run(cmd, env=env | {"RUST_LIBC_UNSTABLE_LINUX_TIME_BITS64": "1"})
-
     if "gnu" in target_env and target_bits == "32":
         # Equivalent of _FILE_OFFSET_BITS=64
         run(cmd, env=env | {"RUST_LIBC_UNSTABLE_GNU_FILE_OFFSET_BITS": "64"})