[PATCH] Add REGISTERS_CLOBBERED_BY_SYSCALL for x86-64

[Rich Felker]

On Tue, Dec 15, 2015 at 12:57:25PM -0800, H.J. Lu wrote:
> X86-64 system calls use a different calling convention, which clobbers
> CC, %r11 an %rcx registers.  Define REGISTERS_CLOBBERED_BY_SYSCALL for
> x86-64 inline asm statements.
> 
> Tested on x86-64.  OK for master?

I don't object, but is there a purpose to it? I agree the "different"
wording is confusing since there's normally no reason to expect
syscalls to look anything like function calls.

Rich