[FR]: Support generating coverage data from deathtests

[thirtytwobits]

Does the feature exist in the most recent commit?

no

Why do we need this feature?

to include death tests in coverage reports

Describe the proposal.

Currently --coverage instrumented code fails – on linux and mac (Have not tested windows) using either clang or gcc – when running death tests because the forked process writes coverage data for the translation unit which causes a failure when the parent (test) process tries to rewrite that coverage data.

By looking at the libgcov interface it does seem this was recently accommodated but my attempts to apply this fix locally have failed.

I'm opening this request in the hopes someone smarter than me knows how to fix this.

Is the feature specific to an operating system, compiler, or build system version?

found problem and tried (but failed) to fix on:

	osx	ubuntu	windows
gcc 10	✓	✓	x
gcc 11	x	✓	x
clang 14	✓	x	x
clang 15	x	✓	x