Add /dev directory which was erronously removed from Linux chroots.

(cherry picked from commit a0947389e55f065f6e2507412aa68f92ec1e496b)
Make pseudo random data inside chroot for platforms that lack it.

(cherry picked from commit b27144404f6e1d8cdeaf32695b95cb95473ee5c9)
Disable parallel builds for deps, since not all of them support it.

(cherry picked from commit e183e872758de1646f023db48a478a33e3582777)
Make MAKEFLAGS and LD_ALTEXEC inheritable in the chroot environment.

(cherry picked from commit 2c4e7c92ce4cdc6328ee47807f0af70eef6327c3)
Put full path to make in MAKE variable.

Otherwise we risk that later assignments to the PATH variable changes
the version we use.

(cherry picked from commit 5aa6a45c0ccd20a50678ed8eb7f575c6c5affc4d)
Disable checksum for LMDB tarball.

Since it is downloaded directly from the git tarball generator, its
checksum may change due to differing timestamps or internal file
order. But we are downloading a direct Git SHA, so we trust that the
contents are the same.

(cherry picked from commit 5765bdeef0bd0c74b33340a480047afe933816be)