outdated/mixer: Post-SVN tidy

- Move source code from `trunk` into root directory.
- Update build files and ASM include paths.

programs/other/outdated/mixer/Tupfile.lua

@@ -1,5 +1,5 @@
 if tup.getconfig("NO_FASM") ~= "" then return end
-HELPERDIR = (tup.getconfig("HELPERDIR") == "") and "../../../.." or tup.getconfig("HELPERDIR")
+HELPERDIR = (tup.getconfig("HELPERDIR") == "") and "../../.." or tup.getconfig("HELPERDIR")
 tup.include(HELPERDIR .. "/use_fasm.lua")
 add_include(tup.getvariantdir())
 

programs/other/outdated/mixer/mixer.asm

@@ -1,3 +1,4 @@
+; SPDX-License-Identifier: NOASSERTION
 
 ;
 ;    MIXER
@@ -6,7 +7,7 @@
 ;
 
 include 'lang.inc'
-include '..\..\..\..\macros.inc'
+include '..\..\..\macros.inc'
 
 
 use32