Update the stdsimd submodule

Add a new cmpxchg16b intrinsics for x86_64!
rust-lang · bors · Jan 5, 2019 · Dec 1, 2018 · Dec 29, 2018 · Dec 30, 2018
commit c0662a033e53106465c75b44adfa6a14304ea1ac
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
@@ -110,6 +110,7 @@
 #![feature(aarch64_target_feature)]
 #![feature(wasm_target_feature)]
 #![feature(avx512_target_feature)]
+#![cfg_attr(not(stage0), feature(cmpxchg16b_target_feature))]
 #![feature(const_slice_len)]
 #![feature(const_str_as_bytes)]
 #![feature(const_str_len)]

diff --git a/src/stdsimd b/src/stdsimd