this is inserted in the analysis pass into a map from expr ptrs to
metadata in the compilation context itself, this enables codegen to
fetch that metadata with the expr pointer
the other approach was embedding it into the variable expr itself (as
seen by VariableExpr), but that causes a compiler crash
- remove Logical expressions
- add basic token return type to LLVMTypeRef converter
- add codegen for Bool literals
- fix "and" and "or" being identified as identifiers