* sysdeps/m68k/lshift.S: Likewise.
* sysdeps/m68k/rshift.S: Likewise.
* sysdeps/m68k/sub_n.S: Likewise.
* sysdeps/m68k/m68020/addmul_1.S: Likewise.
* sysdeps/m68k/m68020/mul_1.S: Likewise.
* sysdeps/m68k/m68020/submul_1.S: Likewise.
* sysdeps/unix/sysv/linux/m68k/sysdep.S: Use ENTRY macro.
[_LIBC_REENTRANT]: Don't store into global errno.
* sysdeps/m68k/sysdep.h: New file.
* sysdeps/unix/sysv/linux/m68k/sysdep.h: Use it. Use the macros
ENTRY, CALL_MCOUNT, JUMPTARGET and syscall_error from there.
(DO_CALL): Change to expect syscall name as argument.
(PSEUDO): Pass syscall_name to DO_CALL.
(SYSCALL_ERROR_HANDLER) [_LIBC_REENTRANT]: Don't store into global
errno.