Rewrite everything to use [] instead of vec() in value position.

src/lib/linux_os.rs

@@ -65,7 +65,7 @@ fn dylib_filename(str base) -> str {
 }
 
 fn pipe() -> tup(int, int) {
-    let vec[mutable int] fds = vec(mutable 0, 0);
+    let vec[mutable int] fds = [mutable 0, 0];
     assert (os::libc::pipe(_vec::buf(fds)) == 0);
     ret tup(fds.(0), fds.(1));
 }
@@ -75,7 +75,7 @@ fn fd_FILE(int fd) -> libc::FILE {
 }
 
 fn waitpid(int pid) -> int {
-    let vec[mutable int] status = vec(mutable 0);
+    let vec[mutable int] status = [mutable 0];
     assert (os::libc::waitpid(pid, _vec::buf(status), 0) != -1);
     ret status.(0);
 }