New syntax for async

Author: phischu

libraries/common/io/network.effekt

@@ -53,45 +53,45 @@ namespace internal {
     declare void @c_tcp_shutdown(%Int, %Stack)
   """
 
-  extern async def connect(host: String, port: Int): Int =
+  extern def connect(host: String, port: Int) at async: Int =
     llvm """
       call void @c_tcp_connect(%Pos ${host}, %Int ${port}, %Stack %stack)
       ret void
     """
 
   /// The buffer must be kept alive by using it after the call
-  extern async def read(handle: Int, buffer: ByteArray, offset: Int, size: Int): Int =
+  extern def read(handle: Int, buffer: ByteArray, offset: Int, size: Int) at async: Int =
     llvm """
       call void @c_tcp_read(%Int ${handle}, %Pos ${buffer}, %Int ${offset}, %Int ${size}, %Stack %stack)
       ret void
     """
 
   /// The buffer must be kept alive by using it after the call
-  extern async def write(handle: Int, buffer: ByteArray, offset: Int, size: Int): Int =
+  extern def write(handle: Int, buffer: ByteArray, offset: Int, size: Int) at async: Int =
     llvm """
       call void @c_tcp_write(%Int ${handle}, %Pos ${buffer}, %Int ${offset}, %Int ${size}, %Stack %stack)
       ret void
     """
 
-  extern async def close(handle: Int): Unit =
+  extern def close(handle: Int) at async: Unit =
     llvm """
       call void @c_tcp_close(%Int ${handle}, %Stack %stack)
       ret void
     """
 
-  extern io def bind(host: String, port: Int): Int =
+  extern def bind(host: String, port: Int) at io: Int =
     llvm """
       %result = call %Int @c_tcp_bind(%Pos ${host}, %Int ${port})
       ret %Int %result
     """
 
-  extern async def listen(listener: Int, handler: Int => Unit at {io, async, global}): Int =
+  extern def listen(listener: Int, handler: Int => Unit at {io, async, global}) at async: Int =
     llvm """
       call void @c_tcp_listen(%Int ${listener}, %Pos ${handler}, %Stack %stack)
       ret void
     """
 
-  extern async def shutdown(handle: Int): Unit =
+  extern def shutdown(handle: Int) at async: Unit =
     llvm """
       call void @c_tcp_shutdown(%Int ${handle}, %Stack %stack)
       ret void