Also includes a few semantic tests which were not already merged into the shared repo.

Create more semantic testcases from the feedback

See merge request !42

adding checks for invalid and valid negative Integers

See merge request !41

Even more semantic tests

See merge request !40

Closes #9

Group 5: Additional semantic test cases

See merge request !39

Test cases from group 3

See merge request !34

More semantic tests

See merge request !38

this is a squased commit with testcases for semantic from group1

See merge request !30

Supplemental semantic test cases

See merge request !37

Programs that contain unreachable code are semantically valid MiniJava
according to the latest clarification of the language specification.

Group 5: Semantic test cases

See merge request !32

Fix access to non-static method/field from static context in namespaces test case

See merge request !36

Semantic tests from the Rust team

See merge request !35

group6 semantic test cases

See merge request !33