patch 8.1.0346: building with Aap is outdated and unused

Problem:    Building with Aap is outdated and unused.
Solution:   Remove the Aap build files.

src/testdir/main.aap

@@ -1,57 +0,0 @@
-#
-# Makefile to run all tests for Vim
-#
-
-VimProg ?= ../vim
-
-Scripts = test1.out test2.out test3.out test6.out
-		test11.out
-		test13.out test14.out test17.out
-		test18.out test21.out
-		test27.out test29.out test30.out
-		test37.out
-		test39.out test42.out
-		test44.out test46.out test47.out
-		test48.out test49.out test74.out
-
-ScriptsGUI = test16.out
-
-# Build "nongui" when no target was specified.
-nongui:	newlog $Scripts
-	:print
-	:cat test.log
-	:print ALL DONE
-
-# Build "ngui" when specified.
-gui:	newlog $Scripts $ScriptsGUI
-	:print
-	:cat test.log
-	:print ALL DONE
-
-$Scripts $ScriptsGUI: $VimProg
-
-clean:
-	:del {r}{force} *.out test.log tiny.vim small.vim mbyte.vim mzscheme.vim test.ok X*
-
-# test1 is special, it checks for features
-test1.out: test1.in
-	:del {force} test1.failed tiny.vim small.vim mbyte.vim mzscheme.vim
-	:sys {i} $VimProg -u unix.vim -U NONE --noplugin -s dotest.in test1.in
-	@if os.system("diff test.out test1.ok") != 0:
-		:error test1 FAILED - Something basic is wrong
-	:move {force} test.out test1.out
-	:del {r}{force} X*
-
-:rule %.out : %.in
-	:del {force} $(match).failed test.ok
-	:copy $(match).ok test.ok
-	:sys {i} $VimProg -u unix.vim -U NONE --noplugin -s dotest.in $(match).in
-	@if os.system("diff test.out " + match + ".ok") != 0:
-		:print $match FAILED >>test.log
-		:move {force} test.out $(match).failed
-	@else:
-		:move {force} test.out $(match).out
-	:del {r}{force} X* test.ok
-
-newlog:
-	:print Test results: >! test.log