Support portable boot files on more platforms #26

Job	Run time
ci (tpb, ubuntu-22.04, --pb --threads --enable-libffi, test-some-fast)	39m 28s
ci (a6osx, macos-12)	14m 26s
ci (ta6osx, macos-12)	18m 58s
ci (i3le, ubuntu-22.04)	15m 51s
ci (ti3le, ubuntu-22.04)	20m 33s
ci (a6le, ubuntu-22.04)	13m 38s
ci (ta6le, ubuntu-22.04)	18m 42s
ci (ta6le, ubuntu-22.04, reboot, -m=ta6le --force, re.boot SCHEME="chezscheme", test-some-fast)	15m 7s
ci (i3nt, windows-2022, vs)	28m 14s
ci (ti3nt, windows-2022, vs)	34m 55s
ci (a6nt, windows-2022, vs)	28m 39s
ci (ta6nt, windows-2022, vs)	35m 3s
ci (ta6nt, windows-2022, gcc)	20m 19s
	5h 3m 53s

Provide feedback