move more native "rust" to native "c-stack-cdecl"

src/lib/linux_os.rs

@@ -72,7 +72,7 @@ fn waitpid(pid: int) -> int {
     ret status;
 }
 
-native "rust" mod rustrt {
+native "c-stack-cdecl" mod rustrt {
     fn rust_getcwd() -> str;
 }
 

src/lib/macos_os.rs

@@ -71,7 +71,7 @@ fn waitpid(pid: int) -> int {
     ret status;
 }
 
-native "rust" mod rustrt {
+native "c-stack-cdecl" mod rustrt {
     fn rust_getcwd() -> str;
 }
 

src/lib/win32_os.rs

@@ -79,7 +79,7 @@ fn fd_FILE(fd: int) -> libc::FILE {
     ret str::as_buf("r", {|modebuf| libc::_fdopen(fd, modebuf) });
 }
 
-native "rust" mod rustrt {
+native "c-stack-cdecl" mod rustrt {
     fn rust_process_wait(handle: int) -> int;
     fn rust_getcwd() -> str;
 }