Expose compile build flag as ENV

What does this MR do?

Exposes compile CLI option as ENV variable to conform with our interface and usage expectations. Also adds some test coverage for analyze since we had none previously.

What are the relevant issue numbers?

Relates to gitlab-org/gitlab#195252 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template (also in CE)
  • Job definition example
  • CI Templates (to be removed)
  • Vendored CI Templates (also in CE)
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer