Don't perform extra go env calls in go/packages.
Load only needed go env vars in golangci-lint.
Stay in sync by enabled analyzers in go vet: remove nilness and
atomicalign analyzers, add errorsas analyzer.
Don't build SSA for govet.
Standalone govet runs 25% faster than before. All runs can be 5-10% faster
than before.
Relates: #208
1. Support unparam linter and fix found issues
2. Replace forked mvdan.cc/lint and mvdan.cc/interfacer with the
upstream ones
3. Minimize forked megacheck: move the most of it's code to this repo
4. Use golang.org/x/tools/go/ssa import path instead of custom fork
paths
5. In golang.org/x/tools/go/{ssa,callgraph} use changed code from
honnef.co/go/tools
6. Add megacheck.check-unexported option: it found some issues in
the repo, fixed them all
1. Log all warnings, don't hide none of them
2. Write fatal messages (stop analysis) with error log level
3. Remove ugly timestamp counter from logrus output
4. Print nested module prefix in log
5. Make logger abstraction: no global logging anymore
6. Refactor config reading to config.FileReader struct to avoid passing
logger into every function
7. Replace exit codes hardcoding with constants in exitcodes package
8. Fail test if any warning was logged
9. Fix calculation of relative path if we analyze parent dir ../
10. Move Runner initialization from Executor to NewRunner func
11. Log every AST parsing error
12. Properly print used config file path in verbose mode
13. Print package files if only 1 package is analyzedin verbose mode,
print not compiling packages in verbose mode
14. Forbid usage of github.com/sirupsen/logrus by DepGuard linter
15. Add default ignore pattern to folint: "comment on exported const"
Don't typecheck func bodies for non-local packages.
Works only if megacheck and interfacer are disabled: they require all
func bodies to build SSA repr.
Export GL_DEBUG=load to get logs for this feature.
