Left-to-right test

[pjuftring]

This tests, if all arithmetic instructions evaluate their operands from left to right.

At the moment, I try to implement as many tests mentioned in TestingTodo.md as I can. I hope, that's ok :)
Should I make a pull request for each test, or wait until I have a bunch of tests and make a Pull Request for all of them together?

[sunfishcode]

For consistency with the overall style of the tests in this directory, please put spaces between operands.

[sunfishcode]

Other than one comment above, lgtm. Implementing tests in TestingTodo.md is great! Submitting test cases either individually or in groups is fine with me.

FYI, I'm also writing some tests -- #113 -- so if there are specific things you're interested in working on, let me know and we can coordinate and avoid duplicating effort.

[sunfishcode]

lgtm; thanks!

[pjuftring]

@sunfishcode You said, I should let you know on which tests I'm working at the moment. So here is a list of tests I'm interested in/working on:
(I'm not sure if this is the right place to post this, should I have opened an "Issue" for that?)

• test that call and store operands are evaluated left-to-right too
• test that page_size returns a power of 2
• test that one can clobber the entire contents of the linear memory without corrupting: call stack, global variables, local variables, program execution.
• test that converting int32 to float and back isn't folded away
• test that converting int64 to double and back isn't folded away

[sunfishcode]

Great! I've now created #132 to serve as a central place for discussing writing tests for the remainder of TestingTodo.md going forward.