__attribute__((regparm(x))) should be only used on i386/x86_64 or removed at all

[Roman Tsisyk]

The attribute does not compile on other archiecture.
regparm (number)
    On the Intel 386, the regparm attribute causes the compiler to pass arguments number one to number if they are of integral type in registers EAX, EDX, and ECX instead of on the stack. Functions that take a variable number of arguments continue to be passed all of their arguments on the stack.

In our case regparm is looking totally useless. I propose to remove it.