Many compilers may optimize away the overflow check `msg + l < msg',
where `msg' is a pointer and `l' is an integer, because pointer
overflow is undefined behavior in C.
Use a safe precondition test `l >= eom - msg' instead.
Reference:
https://android-review.googlesource.com/#/c/50570/
Requested by: pfg
Obtained from: NetBSD (CVS rev. 1.10)
if not already defined. This allows building libc from outside of
lib/libc using a reach-over makefile.
A typical use-case is to build a standard ILP32 version and a COMPAT32
version in a single iteration by building the COMPAT32 version using a
reach-over makefile.
Obtained from: Juniper Networks, Inc.
