Filename extension for S-expression test files

[sunfishcode]

The test files in ml-proto/test were originally name with a '.wasm' extension. However, we might expect .wasm to eventually be the filename extension for the official binary format. I propose we use '.wase' for the S-expression text format.

I accidentally committed a patch implementing this to master in be2b6ea which renames the files to '.wase', rather than submitting a pull request. I'm happy to revert it, or I'm happy to submit a new patch using some other extension, following whatever consensus we get here.

[lukewagner]

Good point, this has been bugging me too for a while. .wase sounds ok to me, although I would have gone with .wast (Wasm AST or WASm Test).

[rossberg]

I like .wast.

[sunfishcode]

'.wast' works for me. I submitted #100 to implement it.

[sunfishcode]

#100 is merged. Thanks!