Operator emit negative values

[samphunter]

Issue description:

Some emit instructions that should take negative integers don't. For example ADDR.pri -20, LOAD.S.pri -20, STOR.S.pri -20, ...

Minimal complete verifiable example (MCVE):

main() {
	emit STACK -20; // Allocate 5 cells
	emit ADDR.alt -20; // Get address of this array of 5 cells
        emit ZERO.pri;
	emit FILL 20; // Fill it with zeros
	emit STOR.S.pri -20; // Access first element
	emit STACK 20; // Free
}

Workspace Information:

• Compiler version: 3.10.9
• Command line arguments provided (or sampctl version): -;+ -(+
• Operating System: Windows 8.1

[YashasSamaga]

#emit supports negative values but the emit operator doesn't.

@Daniel-Cortez

[Daniel-Cortez]

Already did the relevant changes locally, I'll probably upload another batch of improvements for emit tomorrow, but again, it would rely on #393 being merged (I wonder what still keeps it from being merged), as I've added a new token (teREFERENCE).

[Daniel-Cortez]

Fixed in #421.