ash: [EVAL] Pass EV_TESTED into evalcmd

ash: [EVAL] Pass EV_TESTED into evalcmd

Upstream commit:

    Date:   Tue Aug 11 20:48:15 2009 +1000
    [EVAL] Pass EV_TESTED into evalcmd

    This patch fixes the case where the eval command is used with
    set -e and as part of a construct that should not cause the
    shell to abort, e.g., as part of the condition of an if statement.

    This is achieved by propagating the EV_TESTED flag into the
    evalstring function through evalcmd.  As this alters the prototype
    of evalcmd it is now invoked explicitly by evalbltin.  The built-in
    infrastructure has been changed to accomodate this special case.

    In order to ensure that the EXIT trap is properly executed this
    patch clears evalskip in exitshell.  This wasn't needed before
    because of the broken way evalstring worked where it always clears
    evalskip when called by minusc.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Although, I failed to create a reproducer for this.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>