arm (M1?) support

[remram44]

A bit hard to test without access to an M1 myself, but maybe other ARM platforms can be tried through qemu?

This would also need some support in the unpackers, reproducing cross-architecture probably doesn't work now.

Relevant part in tracer, currently supporting x86 and x86_64, which has to be extended:

reprozip/reprozip/native/tracer.c

Lines 453 to 511 in 4603f56

	#if defined(I386)
	if(!process->in_syscall)
	process->current_syscall = regs.orig_eax;
	if(process->in_syscall)
	get_i386_reg(&process->retvalue, regs.eax);
	else
	{
	get_i386_reg(&process->params[0], regs.ebx);
	get_i386_reg(&process->params[1], regs.ecx);
	get_i386_reg(&process->params[2], regs.edx);
	get_i386_reg(&process->params[3], regs.esi);
	get_i386_reg(&process->params[4], regs.edi);
	get_i386_reg(&process->params[5], regs.ebp);
	}
	process->mode = MODE_I386;
	#elif defined(X86_64)
	/* On x86_64, process might be 32 or 64 bits */
	/* If len is known (not 0) and not that of x86_64 registers,
	* or if len is not known (0) and CS is 0x23 (not as reliable) */
	if( (len != 0 && len != sizeof(regs))
	|| (len == 0 && regs.cs == 0x23) )
	{
	/* 32 bit mode */
	struct i386_regs *x86regs = (struct i386_regs*)&regs;
	if(!process->in_syscall)
	process->current_syscall = x86regs->orig_eax;
	if(process->in_syscall)
	get_i386_reg(&process->retvalue, x86regs->eax);
	else
	{
	get_i386_reg(&process->params[0], x86regs->ebx);
	get_i386_reg(&process->params[1], x86regs->ecx);
	get_i386_reg(&process->params[2], x86regs->edx);
	get_i386_reg(&process->params[3], x86regs->esi);
	get_i386_reg(&process->params[4], x86regs->edi);
	get_i386_reg(&process->params[5], x86regs->ebp);
	}
	process->mode = MODE_I386;
	}
	else
	{
	/* 64 bit mode */
	if(!process->in_syscall)
	process->current_syscall = regs.orig_rax;
	if(process->in_syscall)
	get_x86_64_reg(&process->retvalue, regs.rax);
	else
	{
	get_x86_64_reg(&process->params[0], regs.rdi);
	get_x86_64_reg(&process->params[1], regs.rsi);
	get_x86_64_reg(&process->params[2], regs.rdx);
	get_x86_64_reg(&process->params[3], regs.r10);
	get_x86_64_reg(&process->params[4], regs.r8);
	get_x86_64_reg(&process->params[5], regs.r9);
	}
	/* Might still be either native x64 or Linux's x32 layer */
	process->mode = MODE_X86_64;
	}
	#endif