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

///
/// This function should not be inlined because it is cold and it inlining just
/// bloats code.
@noreturn @inline(never)
@_semantics("stdlib_binary_only")
@_semantics("arc.programtermination_point")

  Builtin.int_trap()
}

// FIXME(ABI): rename to something descriptive.
@noreturn
public // COMPILER_INTRINSIC
func _undefined<T>(
