Revert "Fix abi for wasm-bindgen"

This reverts commit 4d2766e352.

compiler/rustc_middle/src/ty/layout.rs

@@ -2752,14 +2752,6 @@ where
                 attrs
             });
 
-            if target.arch == "wasm32" && target.os == "unknown" {
-                // wasm-bindgen depends on ABI details and is incompatible with the
-                // correct C ABI, so this is being kept around until wasm-bindgen
-                // can be fixed to work with the correct ABI. See #63649 for further
-                // discussion.
-                arg.mode = PassMode::Direct(ArgAttributes::new());
-            }
-
             if arg.layout.is_zst() {
                 // For some forsaken reason, x86_64-pc-windows-gnu
                 // doesn't ignore zero-sized struct arguments.