Code coverage for bun test

[Jarred-Sumner]

What does this PR do?

This is an extremely WIP PR that lets you see what code ran in bun test.

This adds a new flag --coverage to bun test which enables JavaScriptCore's JSC::ControlFlowProfiler which tracks the positions (byte offsets) of code that was executed and how many times.

The hard part here is not the code coverage, but is source-mapping from these byte offsets to line numbers in the input source file.

I see a couple approaches to solving this:

1. Store byte ranges in sourcemaps, in addition to lines and columns (expensive!)
2. JSC::SourceProviderCache maybe??

How did you verify your code works?

Too manually. We need some integration tests for this.

[github-actions]

❌ @Jarred-Sumner 1 files with test failures on linux-x64-baseline:

• test/js/third_party/prisma/prisma.test.ts

View test output

^{#9deca0a57b80e87731a42b0ff09646575ea2b8e5}

[github-actions]

❌ @Jarred-Sumner 1 files with test failures on linux-x64:

• test/js/third_party/prisma/prisma.test.ts

View test output

^{#9deca0a57b80e87731a42b0ff09646575ea2b8e5}

[github-actions]

❌ @Jarred-Sumner 2 files with test failures on bun-darwin-aarch64:

• test/js/bun/test/test-test.test.ts
• test/js/node/dns/node-dns.test.js

View test output

^{#9deca0a57b80e87731a42b0ff09646575ea2b8e5}

[github-actions]

❌ @Jarred-Sumner 4 files with test failures on bun-darwin-x64-baseline:

• test/js/bun/spawn/spawn-streaming-stdin.test.ts
• test/js/bun/sqlite/sqlite.test.js
• test/js/third_party/webpack/webpack.test.ts
• test/js/web/timers/setTimeout.test.js

View test output

^{#9deca0a57b80e87731a42b0ff09646575ea2b8e5}

[Jarred-Sumner]

Fixes #2311
Fixes #3158