[SR-4595] Tests generate lots of warnings

[dabrahams]

Previous ID	SR-4595
Radar	None
Original Reporter	@dabrahams
Type	Bug

Additional Detail from JIRA

Votes	0
Component/s	Project Infrastructure
Labels	Bug, StarterBug
Assignee	None
Priority	Medium

md5: 3bb31b4381d569556f0d983141a18d9c

Issue Description:

Because tests pass even when they produce warnings, most people don't see this, but when a test fails, it really matters that the important information is not buried under a bunch of irrelevancies. We need both:

1. To clean up all the existing warnings in tests (obviously, other than those that are part of what we're testing for, and while keeping the tests running)

2. To put a system in place that will cause us to keep the tests clean of warnings.

[belkadan]

Note that this isn't true for all tests; there are some that use deliberately bad code to stress the parser and type-checker. But this doesn't apply to most execution tests, at least (those that use %target-run).