Update libc

The new version of libc contains changes necessary to build
wasmer-runtime-core for Android.

See https://github.com/rust-lang/libc/pull/1622 for details.

Cargo.lock

@@ -749,8 +749,7 @@ dependencies = [
 [[package]]
 name = "libc"
 version = "0.2.67"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb147597cdf94ed43ab7a9038716637d2d1bf2bc571da995d0028dec06bd3018"
+source = "git+https://github.com/rust-lang/libc.git#b22922f7d86a7e5cccc7bc039a375b23d11436b4"
 
 [[package]]
 name = "llvm-sys"

lib/runtime-core/Cargo.toml

@@ -16,8 +16,7 @@ wasmparser = "0.51.3"
 parking_lot = "0.10.0"
 lazy_static = "1.4"
 errno = "0.2"
-#libc = "0.2.60"
-libc = { path = "../../../libc", version = "0.2.65" }
+libc = "0.2.68"
 hex = "0.4"
 smallvec = "0.6"
 bincode = "1.1"

lib/singlepass-backend/Cargo.toml

@@ -17,7 +17,7 @@ dynasmrt = "0.5"
 lazy_static = "1.4"
 byteorder = "1.3"
 nix = "0.15"
-libc = "0.2.60"
+libc = "0.2.68"
 smallvec = "0.6"
 serde = "1.0"
 serde_derive = "1.0"