bug#72384: srfi-64: test-end should not clear fail list

Hello,

I think I found a bug in (srfi srfi-64) module shipped with GNU Guile.

Reading the specification for test-expect-fail I do not see a mandate to clear
expect-fail list on test-end.  test-skip does have such provision, but it is
lacking in the test-expect-fail.  Therefore I think current behavior is wrong:

    (use-modules (srfi srfi-64))

    (test-begin "x")

    (test-begin "group1")
    (test-expect-fail "test-a")
    (test-assert "test-a" #t)
    (pk (test-result-kind))
    (test-end "group1")
    (test-assert "test-a" #t)
    (pk (test-result-kind))

    (test-end)

Leading to:

    ;;; (xpass)

    ;;; (pass)

Have a nice day
Tomas Volf