ash: builtin: Mark more regular built-ins

Upstream commit:

    Date: Sat, 19 May 2018 02:39:49 +0800
    builtin: Mark more regular built-ins

    This patch marks the following built-ins as regular, meaning that
    they cannot be overriden using PATH search:

            hash
            pwd
            type
            ulimit

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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