Align stack on x86_64

Makefile

@@ -54,7 +54,7 @@ $(BUILD)/debug/libc.a: $(SRC)
 	touch $@
 
 $(BUILD)/debug/crt0.o: $(SRC)
-	CARGO_INCREMENTAL=0 cargo --verbose --verbose rustc --manifest-path src/crt0/Cargo.toml $(CARGOFLAGS) -- --emit obj=$@
+	CARGO_INCREMENTAL=0 cargo rustc --manifest-path src/crt0/Cargo.toml $(CARGOFLAGS) -- --emit obj=$@
 	touch $@
 
 $(BUILD)/release/libc.a: $(SRC)

src/crt0/src/lib.rs

@@ -15,6 +15,7 @@ use platform::types::*;
 pub unsafe extern "C" fn _start() {
     #[cfg(target_arch = "x86_64")]
     asm!("mov rdi, rsp
+        and rsp, 0xFFFFFFFFFFFFFFF0
         call _start_rust"
         :
         :