Revert "Fix relative paths in wasm backend source maps. Fixes #9837"

[sbc100]

Reverts #9882

This broke the windows build:
https://chromium-review.googlesource.com/c/emscripten-releases/+/1940591
https://logs.chromium.org/logs/emscripten-releases/buildbucket/cr-buildbucket.appspot.com/8895598112699504816/+/steps/Emscripten_testsuite__upstream__other_/0/stdout

[kripken]

Another option than reverting it is this possible fix https://github.com/emscripten-core/emscripten/compare/map2?expand=1 which I am waiting on tests for.

Based on the logs and reading the code, I think that should work, however I don't have a windows machine to test on. If you want to play it safe then I guess we can just revert.

[sbc100]

If you can verify the fix then I think we should land the fix yes. I we can't verify the fix on the windows machine i worry that we will up committing bunch of speculative fixes that might or might not pass on windows.

The cost of reverting and re-landing in pretty low so I'm tempted to revert. I also think its a good habit to get into too.

[sbc100]

That fix still looks odd to me: r'(?im)in main (|[/a-z\.\\]:).*test_lsan_leaks\.c:10:16$',

The second pair of brackets is supposed to match either a driver letter plus a colon or the start of a path (either abs or rel).

It seems to me like it should be more like (\.|\/|[a-z]:) to represents the three different ways to start a path?

[sbc100]

Maybe simpler just to do .*test_lsan_leaks.....?

[kripken]

Yeah, the square brackets could be adjusted and the regex cleaned up I guess. But meanwhile I realized the regex doesn't need to be changed at all - this should be just a 1-line fix.

I'd suggest landing that, but again, if you prefer to revert the original and delay everything til next week, I'm fine with that too.

I'm not sure what you're suggesting in the last comment?

[sbc100]

Happy to land you one line fix.

We should definitely cleanup the regex though. Right now its seem to be looking for driver letter a-z but also . and / as driver letters, which makes no sense.