* Don't run go fmt error in go_utils.py
go_utils.py currently runs go fmt to pretty print the generated
inst.go file. Unfortunately, this call to go fmt always fails as
inst.go contains an internal import and go fmt is being run out of
tree. Here we remove the code that attempts to format inst.go
resulting in a clean run of go_utils.py without any errors. The
generated file, inst.go, can be formatted when it's copied into the
Go source tree, prior to its submission to the Golang project.
* Add CSR support to go_utils.py
go_utils.py now generates a Go map that maps CSR numbers to CSR
names. The resulting map is written into inst.go for use by the
Go assembler.
* Remove wildcard imports
Use explicit imports rather than wildcards. This is more maintainable.
* Enable Pylint in CI and fix its errors
The main fixes were:
* Specify encoding for all file opens. By default it depends on environment variables which is bad.
* Use `with` to open files. Otherwise they don't necessarily get closed.
There were also a few minor things like using `enumerate`, not using objects as default arguments, etc. In some cases I slightly refactored the code.
This makes the code easier to understand and navigate, and also detected a few of bugs:
1. Missing brackets on e.upper. (Fixed)
2. Not strictly related to types, but a lot of the regexes were not raw strings and therefore contained invalid escape sequences. Python prints a warning about these in recent versions. (Fixed)
3. Expression in `process_pseudo_instructions()` that is always false. (Not fixed)
4. Missing definition of `log_and_exit()`. (Fixed)
This is validated via pre-commit in CI.
