don't use CFI on OSX. can we detect this with cmake somehow?
ifdef linux specific inotify stuff
don't include folly config
don't build non-portable folly objects
recent upstream folly changes require us to specify that we use sched.h
capability call must be inside define check.
allow compiler  to decide which namespace these come from.

this prevents such errors as "error: 'je_free' is not a member of 'std'"
when jemalloc replaces these built-in functions.
another section that needs a comma
folly should link with jemalloc
dalloc/ralloc are experimental features.
allow osx to generate ext-hhvm
tv helper needs to be explicitly defined
on OSX, Int64 is long long.

I'm not sure if this is the case across the board for all platforms.
I shall let the facebook gurus figure this one out.
don't include elfwriter in vm debug
this assertion is not true on OSX
osx can't decide what overloaded method to use with ssize_t
skip openssl deprecration warnings
we still need to use inline, alongside ALWAYS_INLINE
remove unused variable.
link icudata too, if it can be found.