more memory optimizations

[xiwenc]

No description provided.

[github-actions]

Merging this branch will decrease overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/mxlint/mxlint-cli/mpr	69.63% (-2.00%)	👎

---

Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/mxlint/mxlint-cli/mpr/export_stream.go	33.33% (+1.92%)	195 (+4)	65 (+5)	130 (-1)	👍
github.com/mxlint/mxlint-cli/mpr/microflow.go	66.67% (-13.61%)	6 (-141)	4 (-114)	2 (-27)	💀
github.com/mxlint/mxlint-cli/mpr/mpr.go	79.88% (-0.31%)	507 (-8)	405 (-8)	102	👎
github.com/mxlint/mxlint-cli/mpr/types.go	0.00% (ø)	0	0	0
github.com/mxlint/mxlint-cli/mpr/utils.go	74.51% (-19.69%)	51 (-18)	38 (-27)	13 (+9)	💀

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.

Changed unit test files

• github.com/mxlint/mxlint-cli/mpr/microflow_test.go
• github.com/mxlint/mxlint-cli/mpr/mpr_test.go