Fix wasm_exceptions test

Author: nbdd0121

Diff for: tests/assembly/wasm_exceptions.rs

@@ -6,12 +6,12 @@
 
 #![crate_type = "lib"]
 #![feature(core_intrinsics)]
-#![feature(rustc_attrs)]
 
-extern "C" {
+extern "C-unwind" {
     fn may_panic();
+}
 
-    #[rustc_nounwind]
+extern "C" {
     fn log_number(number: usize);
 }
 

Diff for: tests/codegen/wasm_exceptions.rs

@@ -3,12 +3,12 @@
 
 #![crate_type = "lib"]
 #![feature(core_intrinsics)]
-#![feature(rustc_attrs)]
 
-extern "C" {
+extern "C-unwind" {
     fn may_panic();
+}
 
-    #[rustc_nounwind]
+extern "C" {
     fn log_number(number: usize);
 }