   _ line: UInt, _ column: UInt,
   flags: UInt32)
 
+// FIXME(ABI): add argument labels to conform to API guidelines.
 @_silgen_name("_swift_stdlib_reportUnimplementedInitializer")
 func _reportUnimplementedInitializer(
   className: UnsafePointer<UInt8>, _ classNameLength: UInt,

  Builtin.int_trap()
}

@noreturn
public // COMPILER_INTRINSIC
func _undefined<T>(

///
/// This function should not be inlined because it is cold and it inlining just
/// bloats code.
// FIXME(ABI): add argument labels to conform to API guidelines.
@noreturn @inline(never)
@_semantics("stdlib_binary_only")
@_semantics("arc.programtermination_point")
