Wasm merge loses start function from one of the merged modules

[igoriakovlev]

Using wasm-merge from the fresh binaryen sources (e9b4b4c).
Having a problem that if two modules being merged loses the one of start functions.

Steps to reproduce:

1. Download attached file.
2. node ./run.mjs

Expected:
Both values are equal 2.

Actual:
Splitted modules load have value 2.
Merged modules load have value 1.

[kripken]

How are you linking the files? I tried this:

$ nodejs run.mjs 
Splitted: 2
Merged: 1

$ wasm-merge main.wasm imp second.wasm second -all -o merged.wasm

$ nodejs run.mjs 
Splitted: 2
Merged: 2

The final output is correct, so it looks like my merge command worked? Did you use a different command?

[igoriakovlev]

Yeah, sorry, I make a mistake in command line so I cannot reproduce it now. But anyway, with Kotlin compiled code there is still the issue. To reproduce it you need to:

1. Download the kotlin compiled multimodule here
2. Upack
3. Execute wasm-merge --debuginfo -all --disable-custom-descriptors --skip-export-conflicts kotlin-kotlin-stdlib.wasm '<kotlin>' kotlinx-browser.wasm '<org.jetbrains.kotlinx:kotlinx-browser>' -o merged.wasm
4. wasm-dis merged.wasm -o merged.wat
5. See that result file contains function func $merged.start.new and func $merged.start.old. And the only start.old is now called. start.new function is not called from anywhere.

[kripken]

Thanks @igoriakovlev , now I see the problem. Fix is in #8697