[coreboot-gerrit] Change in coreboot[master]: util/testing: combine code coverage data

[Paul Fagerburg (Code Review)]

Attention is currently required from: Patrick Georgi, Martin Roth, Paul Fagerburg.
Paul Fagerburg has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/59959 )

Change subject: util/testing: combine code coverage data
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Patch Set 2:

(1 comment)

Patchset:

PS2: 
Turned out to be a lot simpler than I expected. I wanted to have one of the `coverage-report` targets gather all of the coverage for the sub-makes, but it turns out you can just `cat` all the LCOV files together.