Get wasm32-wasip2 compiling with its custom pal implementation

The ordering of targets in `pal/mod.rs` did not end up using the wasip2
implementation, so after reordering that I've edited the implementation
to compile correctly.

Author: alexcrichton

library/std/src/sys/pal/mod.rs

@@ -37,12 +37,12 @@ cfg_if::cfg_if! {
     } else if #[cfg(target_os = "hermit")] {
         mod hermit;
         pub use self::hermit::*;
-    } else if #[cfg(target_os = "wasi")] {
-        mod wasi;
-        pub use self::wasi::*;
     } else if #[cfg(all(target_os = "wasi", target_env = "p2"))] {
         mod wasip2;
         pub use self::wasip2::*;
+    } else if #[cfg(target_os = "wasi")] {
+        mod wasi;
+        pub use self::wasi::*;
     } else if #[cfg(target_family = "wasm")] {
         mod wasm;
         pub use self::wasm::*;

library/std/src/sys/pal/wasip2/mod.rs

@@ -10,8 +10,6 @@
 pub mod alloc;
 #[path = "../wasi/args.rs"]
 pub mod args;
-#[path = "../unix/cmath.rs"]
-pub mod cmath;
 #[path = "../wasi/env.rs"]
 pub mod env;
 #[path = "../wasi/fd.rs"]
@@ -28,10 +26,6 @@ pub mod io;
 pub mod net;
 #[path = "../wasi/os.rs"]
 pub mod os;
-#[path = "../unix/os_str.rs"]
-pub mod os_str;
-#[path = "../unix/path.rs"]
-pub mod path;
 #[path = "../unsupported/pipe.rs"]
 pub mod pipe;
 #[path = "../unsupported/process.rs"]