Compiler dies without an error message when declaring func outside of bank

[veremenko-y]

Compiler dies without an error message when declaring func outside of bank

Steps to reproduce:

• Create file bugtest.wiz with the following content

  func main {
  }

• Compile with wiz\wiz.exe src/bugtest.wiz -o bugtest.nes

• Actual output is truncated due to early exit of the compiler

    * wiz: version 0.1.2 (alpha)
    >> Parsing...
    >> Compiling...

• Expected output: error message of misdeclared function