__attribute_const__ for MSVC
minor: __builtin_constant_p availability

remove duplicated preprocessor logic
Sun Studio workaround for __asm__ and __volatile__

Sun Studio C/C++ might not recognize __asm, __asm__, or __volatile__
xlC #include <builtins.h>; avoid <sys/atomic_op.h>

xlC #include <builtins.h>; avoid <sys/atomic_op.h>
document Sun Studio 12.1 support for extended inline asm
add annotation macros for select compiler pragmas
annotate headers with PLASMA_ATTR_Pragma_once
plasma_ident - portability macros for ident string

place ident strings in .comment (or similar) non-loadable binary section
add COPYING and LICENSE files
plasma_endian - byteorder endian conversion macros
employ plasma pragmas and byteorder endian swap
nointr.[ch] - don't inline funcs wrapping syscalls

nointr.[ch] - do not bother inlining funcs wrapping syscalls
remove _ALL_SOURCE define (AIX) where possible

remove _ALL_SOURCE define (AIX) where possible
_XOPEN_SOURCE >= 700 for *at() libc funcs

_XOPEN_SOURCE >= 700 for *at() libc funcs (openat, fstatat, etc)
(The Open Group Technical Standard, 2006, Extended API Set Part 2)
use Linux kernel user helper memory barrier on ARM