rules_go tests failing with Bazel@HEAD

[meteorcloudy]

First reported at bazelbuild/continuous-integration#1429
https://buildkite.com/bazel/bazel-at-head-plus-downstream/builds/2632#01833a2a-4026-47c4-9730-89252449e823

    --- FAIL: TestLcovCoverage/without-race (5.06s)
        lcov_coverage_test.go:171: bazel-testlogs/src/lib_test/coverage.dat: does not contain:
            
            SF:src/other_lib.go
            FNF:0
            FNH:0
            DA:3,1
            DA:4,1
            DA:5,0
            DA:6,0
            DA:7,1
            LH:3
            LF:5
            end_of_record
            
            actual content:
            

//tests/core/coverage:lcov_coverage_test and //tests/core/coverage:lcov_test_main_coverage_test are broken by coverage_output_generator v2.6 introduced at bazelbuild/bazel@a70d84b

(There is another test //tests/core/cross:non_executable_test also failing, but due a Bazel issue, we are investigating)

[meteorcloudy]

/cc @c-mita @fmeum

[fmeum]

This one is on us: We have been lazy about populating InstrumentedFilesInfo since it wasn't necessary until v2.6. Will fix that and look into //tests/core/cross:non_executable_test as well.

[meteorcloudy]

Thanks!
For //tests/core/cross:non_executable_test, we have figured it out, please check bazelbuild/continuous-integration#1429 (comment)