[#4294] --gtest_break_on_failure conflicts with EXPECT_NONFATAL_FAILURE.

[avrdan]

Changes the behavior so that the flags --gtest_break_on_failure and --gtest_throw_on_failure no longer throw or raise signals for non-fatal failure, thus allowing execution to continue.

[higher-performance]

Note that you will almost certainly need to new tests for this (in addition to making sure all the existing ones pass, even disabled ones) to test all the edge cases you can, because I don't think we have tests for all of them here.