Add INTERNAL_SYSCALL_CALL

This patch adds two new macros for internal and inline syscall to use
within GLIBC: INTERNAL_SYSCALL_CALL and INLINE_SYSCALL_CALL.  They are
similar to the old INTERNAL_SYSCALL and INLINE_SYSCALL with the difference
the new macros accept a variable argument call and do not require to pass
the expected argument size.

The advantage is it is possible to use variable argument macros like
SYSCALL_LL{64} without the need to also handle the argument size.  So
for an ABI where SYSCALL_LL might split the argument in high and low
parts, instead of:

  INTERNAL_SYSCALL_DECL (err);
 #if ...
  INTERNAL_SYSCALL (syscall, err, 2, SYSCALL_LL (len));
 #else
  INTERNAL_SYSCALL (syscall, err, 1, SYSCALL_LL (len));
 #endif

It will be just:

  INTERNAL_SYSCALL_CALL (syscall, err, SYSCALL_LL (len));

The INLINE_SYSCALL_CALL follows the same semanthic regarding the argument
and is similar to INLINE_SYSCALL regarding setting errno.

Checked with a build for x86_64, i386, aach64, armhf, powerpc64le, powerpc32,
and mips32.  No code generation changed.

	* sysdeps/unix/sysdep.h (__INTERNAL_SYSCALL0): New macro.
	(__INTERNAL_SYSCALL1): Likewise.
	(__INTERNAL_SYSCALL2): Likewise.
	(__INTERNAL_SYSCALL3): Likewise.
	(__INTERNAL_SYSCALL4): Likewise.
	(__INTERNAL_SYSCALL5): Likewise.
	(__INTERNAL_SYSCALL6): Likewise.
	(__INTERNAL_SYSCALL7): Likewise.
	(__INTERNAL_SYSCALL_NARGS_X): Likewise.
	(__INTERNAL_SYSCALL_NARGS): Likewise.
	(__INTERNAL_SYSCALL_DISP): Likewise.
	(INTERNAL_SYSCALL_CALL): Likewise.
	(__SYSCALL0): Rename to __INLINE_SYSCALL0.
	(__SYSCALL1): Rename to __INLINE_SYSCALL1.
	(__SYSCALL2): Rename to __INLINE_SYSCALL2.
	(__SYSCALL3): Rename to __INLINE_SYSCALL3.
	(__SYSCALL4): Rename to __INLINE_SYSCALL4.
	(__SYSCALL5): Rename to __INLINE_SYSCALL5.
	(__SYSCALL6): Rename to __INLINE_SYSCALL6.
	(__SYSCALL7): Rename to __INLINE_SYSCALL7.
	(__SYSCALL_NARGS_X): Rename to __INLINE_SYSCALL_NARGS_X.
	(__SYSCALL_NARGS): Rename to __INLINE_SYSCALL_NARGS.
	(__SYSCALL_DISP): Rename to __INLINE_SYSCALL_DISP.
	(__SYSCALL_CALL): Rename to INLINE_SYSCALL_CALL.
	(SYSCALL_CANCEL): Replace __SYSCALL_CALL with INLINE_SYSCALL_CALL.