Fix release truncation issue by changing symlinks

[cameel]

Resolves ethereum/solidity#9261. Part of ethereum/solidity#9258.

It's a PR to master but we should backport the fix to gh-pages too.

Cause of the problem

See diuscussion on Gitter

@cameel

ls -la wasm/soljson-*.js

lrwxrwxrwx 1 cameel cameel 34 2020-07-06 17:33 wasm/soljson-latest.js -> soljson-v0.6.10+commit.00c0fcaf.js
lrwxrwxrwx 1 cameel cameel 34 2020-07-06 17:33 wasm/soljson-nightly.js -> soljson-v0.6.10+commit.00c0fcaf.js
lrwxrwxrwx 1 cameel cameel 41 2020-06-30 14:44 wasm/soljson-v0.6.10+commit.00c0fcaf.js -> ../bin/soljson-v0.6.10+commit.00c0fcaf.js

Looks like the solc-bin commit that added Release 0.6.10 replaced wasm/soljson-latest.js and wasm/soljson-nightly.js with symlinks back to files in bin/.

The update script has not been updated to account for that so it still just overwrites them instead of updating the links. They both point at the same file and there are also asynchronous operations trying to read with from the file they're writing to.

So making things synchronous should fix this. But we should probably make the script take links into account instead.

Also, not sure if it's deliberate, but wasm/soljson-nightly.js points at the release file, not at a nightly build. Technically, it's the latest build available in the wasm/ directory but I suspect this was not the intention. Should we really have soljson-nightly.js in that dir if it nightlies are not linked there?

@ekpyron

We should (1) remove wasm/soljson-nightly.js, (2) just keep wasm/soljson-latest.js be a symlink to bin/soljson-latest.js that never changes and (3) remove all logic for soljson-nightly and soljson-latest for wasm/ from the update script.

[ekpyron]

Looks good, if the tests pass!

[chriseth]

Wouldn't it make sense to make all the '-latestand-nightly` files symlinks?

[chriseth]

Ah, that seems to be #33!

[cameel]

Yeah. It wasn't essential to the fix and required more than just removing a few lines from the update script so I put it in a separate PR.

[cameel]

I just merged the master branch (with this PR in it) back into gh-pages. Removing master from the repo now.