MFC r234782:

MFC r234782:
Add src.conf option WITH_SHARED_TOOLCHAIN to enable building the
toolchain binaries as dynamically linked.  Option is disabled by
default.

MFC r235152 (by imp):
Make is part of the bootstrap path, so we need to guard against this
not being defined.  Otherwise we don't make a new make when the old
make is incompatible.

git-svn-id: svn://svn.freebsd.org/base/stable/9@235398 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f