Remove async fn from extern block tests

Author: dtolnay

tests/source/extern.rs

@@ -60,10 +60,6 @@ libc::c_long;
                               -> *mut FILE;
 
 
-       async fn foo(
-
-       ) -> *mut
-       Bar;
        const fn foo(
 
        ) ->
@@ -74,7 +70,6 @@ libc::c_long;
        mut
        Bar;
 
-       pub async fn foo() -> *mut Bar;
        pub(super) const fn foo() -> *mut Bar;
        pub(crate) unsafe fn foo() -> *mut Bar;
    }

tests/target/extern.rs

@@ -74,11 +74,9 @@ extern "C" {
         file: *mut FILE,
     ) -> *mut FILE;
 
-    async fn foo() -> *mut Bar;
     const fn foo() -> *mut Bar;
     unsafe fn foo() -> *mut Bar;
 
-    pub async fn foo() -> *mut Bar;
     pub(super) const fn foo() -> *mut Bar;
     pub(crate) unsafe fn foo() -> *mut Bar;
 }