Add getchar_unlocked and putchar_unlocked

Author: mmun

src/lib.rs

@@ -168,6 +168,8 @@ extern {
     pub fn setbuf(stream: *mut FILE, buf: *mut c_char);
     pub fn getchar() -> c_int;
     pub fn putchar(c: c_int) -> c_int;
+    pub fn getchar_unlocked() -> c_int;
+    pub fn putchar_unlocked(c: c_int) -> c_int;
     pub fn fgetc(stream: *mut FILE) -> c_int;
     pub fn fgets(buf: *mut c_char, n: c_int, stream: *mut FILE) -> *mut c_char;
     pub fn fputc(c: c_int, stream: *mut FILE) -> c_int;