[EH] Convert EH tests into lit tests

[aheejin]

This converts most EH tests in test/passes into test/lit/passes. Fixed
some files to follow 2-space indentation and improved some comments.

[tlively]

Awesome! Besides the edits you mentioned, did you just use the update_lit_checks.py script to do this conversion?

[aheejin]

Except for 2-3 tests yes, which required 1. stack IR printing or 2. module elements printing. They don't have the

;; NOTE: Assertions have been generated by update_lit_checks.py and should not be edited.

at the top.

I thought about not autogenerating the whole function in case it is slightly longer but only adding lines that are relevant, but it was not very easy because in case we want to check this pattern in a function:

(drop
  (i32.add
    (local.get $x)
    (i32.const 3)
  )
)

Simply doing the below doesn't work in a lot of times

;; CHECK:     (drop
;; CHECK-NEXT:  (i32.add
;; CHECK-NEXT:    (local.get $x)
;; CHECK-NEXT:    (i32.const 3)
;; CHECK-NEXT:  )
;; CHECK-NEST: )

because the first (drop can be matched to another line that comes before the part we want to match, and all those CHECK-NEXT will fail. So I found, unlike LLVM in which we don't use autogeneration very often, using the autogeneration script to generate CHECK lines for a whole function was easier. But I think this is still better than .txt files in readability.

[tlively]

Why doesn't this function have check lines? If they were manually deleted, they will come back next time someone runs ./auto_update_tests.py, so it would be better just to keep them in.

[aheejin]

This is strange. update_lit_checks.py actually doesn't update this. Also (func $callee in the same file. Not sure why.

[tlively]

Must be a bug in the regex used by the script. I wouldn't worry about it if those functions aren't critical to the test.

[aheejin]

This indeed can't exist because $callee-with-label is inlined! 🙃

[tlively]

ohhh, that makes sense. Sorry for the confusion!