Bugs in inline assembly for syscall

[173210]

The inline assembly codes not in functions for syscall causes some problems.

• rSyscall will be copied to all object files including syscall.h
  92e42b3#diff-94205e61f849a62cdd2430c5371978b1R7
• Fails linking with link time optimization

The solution is quite a simple: Use __PIC__ macro or define syscall codes as functions.
Defining functions is the easiest way to solve the problem, but it may be a bit slower than using inline assembly code if the calling convention is different from the ordinary one.