__ASSUME_PRIVATE_FUTEX and __ASSUME_FUTEX_CLOCK_REALTIME

[Joseph S. Myers]

__ASSUME_PRIVATE_FUTEX and __ASSUME_FUTEX_CLOCK_REALTIME are defined for 
all supported Linux kernel versions.  Should we say they are a required 
part of the futex interface for any system, whether or not using the Linux 
kernel, that may wish to use NPTL, and so remove these macros and all 
conditionals testing them everywhere in glibc, not just in 
sysdeps/unix/sysv/linux/ files?

-- 
Joseph S. Myers
joseph@codesourcery.com