Remove adjtime for emscripten

Author: guyru

src/unix/mod.rs

@@ -1390,7 +1390,13 @@ extern "C" {
 
     pub fn lockf(fd: ::c_int, cmd: ::c_int, len: ::off_t) -> ::c_int;
 
-    pub fn adjtime(delta: *const timeval, olddelta: *mut timeval) -> ::c_int;
+}
+cfg_if! {
+    if #[cfg(not(target_os = "emscripten"))] {
+        extern "C" {
+            pub fn adjtime(delta: *const timeval, olddelta: *mut timeval) -> ::c_int;
+        }
+    }
 }
 
 cfg_if! {