Emscripten binaries for version 0.3.6 in solc-bin were not built from the commit tagged as v0.3.6

In solc-bin we have [soljson-v0.3.6+commit.3fc68da5.js](https://github.com/ethereum/solc-bin/blob/gh-pages/bin/soljson-v0.3.6+commit.3fc68da5.js) and [soljson-v0.3.6+commit.3fc68da5.js](https://github.com/ethereum/solc-bin/blob/gh-pages/wasm/soljson-v0.3.6+commit.3fc68da5.js), both built from 3fc68da5. Tag [`v0.3.6`](https://github.com/ethereum/solidity/tree/v0.3.6) points at commit 988fe5e (i.e. one commit after 3fc68da5).

This is a problem because they will produce different bytecode than releases from other platforms built on `v0.3.6` (e.g. the recent macOS rebuilds).

The binaries in solc-bin are not necessarily the files that were released - [release `v0.3.6`](https://github.com/ethereum/solidity/releases/tag/v0.3.6) has no binaries attached at all - so I think we could rebuild on the tag and put both in the repo.

The affected artifacts are soljson-v0.3.6+commit.3fc68da5.js in the solc-bin bin/ and wasm/ paths; start by checking their provenance against tag v0.3.6 and the referenced commits. Rebuild both Emscripten outputs from the tagged commit, place them in solc-bin, and verify they correspond to v0.3.6 without the reported bytecode mismatch.

Written by the indexing model from the issue text.