Use libc for AArch64 consts too

Now that rust-lang/libc#1638 got merged and a
new libc release got made, we can use them instead of hardcoding their
values.

This bumps the libc dependency to the earliest version with these
consts.

sha1/Cargo.toml

@@ -18,7 +18,7 @@ block-buffer = "0.7"
 fake-simd = "0.1"
 sha1-asm = { version = "0.4", optional = true }
 opaque-debug = "0.2"
-libc = { version = "0.2", optional = true }
+libc = { version = "0.2.68", optional = true }
 
 [dev-dependencies]
 digest = { version = "0.8", features = ["dev"] }

sha1/src/aarch64.rs

@@ -1,9 +1,7 @@
-// TODO: Import those from libc, see https://github.com/rust-lang/libc/pull/1638
-const AT_HWCAP: u64 = 16;
-const HWCAP_SHA1: u64 = 32;
+use libc::{getauxval, AT_HWCAP, HWCAP_SHA1};
 
 #[inline(always)]
 pub fn sha1_supported() -> bool {
-    let hwcaps: u64 = unsafe { ::libc::getauxval(AT_HWCAP) };
+    let hwcaps: u64 = unsafe { getauxval(AT_HWCAP) };
     (hwcaps & HWCAP_SHA1) != 0
 }

sha2/Cargo.toml

@@ -15,7 +15,7 @@ block-buffer = "0.7"
 fake-simd = "0.1"
 opaque-debug = "0.2"
 sha2-asm = { version="0.5", optional=true }
-libc = { version = "0.2", optional = true }
+libc = { version = "0.2.68", optional = true }
 
 [dev-dependencies]
 digest = { version = "0.8", features = ["dev"] }

sha2/src/aarch64.rs

@@ -1,9 +1,7 @@
-// TODO: Import those from libc, see https://github.com/rust-lang/libc/pull/1638
-const AT_HWCAP: u64 = 16;
-const HWCAP_SHA2: u64 = 64;
+use libc::{getauxval, AT_HWCAP, HWCAP_SHA2};
 
 #[inline(always)]
 pub fn sha2_supported() -> bool {
-    let hwcaps: u64 = unsafe { ::libc::getauxval(AT_HWCAP) };
+    let hwcaps: u64 = unsafe { getauxval(AT_HWCAP) };
     (hwcaps & HWCAP_SHA2) != 0
 }