live: add ext(.dll/.so) to output name of -live

[kbkpbot]

Fix issue #6936

Now, -live work both under Windows and Linux:

D:\v\v\v>v -live run examples\hot_reload\message.v
OK reloads:    1 | Total reloads:    1 | Hello! Modify this message while the program is running. app: 48e0fd0 | app.x:      0 | app.counter:      0
OK reloads:    1 | Total reloads:    1 | Hello! Modify this message while the program is running. app: 48e0fd0 | app.x:      0 | app.counter:      1
OK reloads:    1 | Total reloads:    1 | Hello! Modify this message while the program is running. app: 48e0fd0 | app.x:      0 | app.counter:      2

D:\v\v\v>v -live run examples\hot_reload\message.v -cc msvc
OK reloads:    1 | Total reloads:    1 | Hello! Modify this message while the program is running. app: 1550fd0 | app.x:      0 | app.counter:      0
OK reloads:    1 | Total reloads:    1 | Hello! Modify this message while the program is running. app: 1550fd0 | app.x:      0 | app.counter:      1
OK reloads:    1 | Total reloads:    1 | Hello! Modify this message while the program is running. app: 1550fd0 | app.x:      0 | app.counter:      2
OK reloads:    1 | Total reloads:    1 | Hello! Modify this message while the program is running. app: 1550fd0 | app.x:      0 | app.counter:      3

$ v -live run examples/hot_reload/message.v
OK reloads:    1 | Total reloads:    1 | Hello! Modify this message while the program is running. app: 755911d62fe0 | app.x:      0 | app.counter:      0
OK reloads:    1 | Total reloads:    1 | Hello! Modify this message while the program is running. app: 755911d62fe0 | app.x:      0 | app.counter:      1
OK reloads:    1 | Total reloads:    1 | Hello! Modify this message while the program is running. app: 755911d62fe0 | app.x:      0 | app.counter:      2

[huly-for-github]

Connected to Huly®: V_0.6-22281

[spytheman]

Excellent work.
Thank you 🙇🏻‍♂️.

[spytheman]

I noticed while testing, that the generated .def file has one additional .dll in it:

It does not affect the work of the live reloader, it just seems weird to me.

[medvednikov]

Great job! Would it be possible to add a test so that it doesn't regress?

Something simple, not graphical, should be doable

[spytheman]

There is vlib/v/live/live_test.v, but it is flaky on windows (fails ~ 1 time out of 15 on windows), so it is skipped.

I do not want to enable it on the CI, to reduce the false positives that otherwise affect other unrelated PRs.