Multi operations

[Konstantin8105]

Add support of next C code

#include <stdio.h>

int main(void)
{
	int x, y, z;
	x = y = z = 5;
	printf("x = %d\ty = %d\tz = %d\n",x,y,z);
	x += y += z += 5;
	printf("x = %d\ty = %d\tz = %d\n",x,y,z);
	x *= y *= z *= 5;
	printf("x = %d\ty = %d\tz = %d\n",x,y,z);
	return 0;
}

Result:

x = 5	y = 5	z = 5
x = 20	y = 15	z = 10
x = 15000	y = 750	z = 50

[Konstantin8105]

Fix #185

[elliotchance]

@Konstantin8105 can this issue be closed now that the pull request is merged in?

[Konstantin8105]

@elliotchance Now, we have only operation Equal.
I will prepare PR for other operations (*= , >>= , .... ).