Enable native debugging for vstest.console

[ocitrev]

Description

With environment variable VSTEST_HOST_NATIVE_DEBUG, we can use a native debugger to debug tests but it requires --InIsolation flag.
When using the argument --tests: to run a specific test, testhost.exe is spawned twice and we must attach twice to properly debug.

When the environment variable VSTEST_RUNNER_DEBUG is set, vstest.console only waits for a managed debugger.

I propose to add new environment variable VSTEST_RUNNER_NATIVE_DEBUG to enable native debugging of vstest.conssole.
This will enable native debugging of tests without the --InIsolation flag.

Related issue

Fixes #10393

• I have ensured that there is a previously discussed and approved issue.

[ocitrev]

@microsoft-github-policy-service agree

[nohwnd]

Thank you.