Compiler cases for symbol and quote

[dylannakahodo]

This pull request is for the implementation of handling symbols and quote expressions in the compiler, I've also added two unit tests for these cases.

• The compiler outputs the (refer x next) expression when given a symbol.

• The compiler outputs the (constant obj next) expression when given a quote expression.

The unit tests check if the string representation of the assembly instructions match what we expect.

Please check if the implementation looks okay and if the unit tests make sense.

Thanks.

[CinchBlue]

Looks good to me. I talked about you with this in person. Approved!