bun-wasm fixes & improvements

[jhmaster2000]

What does this PR do?

• Fix WASM build on Linux by unhardcoding mimalloc filename in Makefile
• Fix most TS errors in bun-wasm, add missing types, stronger types
• Add scripts to document the process of building bun-wasm
• Improve usability of bun-wasm as a proper package:
  • init() can now be called with no args and will resolve to the default location of next to the built index.js
    • The url argument still exists to be used if overriding the default wasm file location is needed.
    • To use the default location and pass the other args such as heap size, null can be given as the url.
  • Split index.d.ts into index.d.cts and index.d.mts, these are exact copies of each other but are necessary for optimal editor intellisense compatibility, as it tries to map the output index.mjs and index.cjs files to definition files of matching extension.

There's also some more isolated bun-polyfills progress as I branched this branch from the bun-polyfills branch by accident but that should be fine. (no bun-types changes included this time)

How did you verify your code works?

Manual testing based on the bun-wasm/test/node.mjs file. (bun-wasm is not part of the test suite yet)

[Jarred-Sumner]

nice

[github-actions]

❌ @jhmaster2000 2 files with test failures on linux-x64-baseline:

• test/js/third_party/esbuild/esbuild-child_process.test.ts
• test/js/third_party/prisma/prisma.test.ts

View test output

^{#a2ff5f6f03526acdd68b2f8977e3395522a39f67}

[github-actions]

❌ @jhmaster2000 2 files with test failures on linux-x64:

• test/js/third_party/esbuild/esbuild-child_process.test.ts
• test/js/third_party/prisma/prisma.test.ts

View test output

^{#a2ff5f6f03526acdd68b2f8977e3395522a39f67}

[github-actions]

❌ @jhmaster2000 3 files with test failures on bun-darwin-aarch64:

• test/js/bun/test/test-test.test.ts
• test/js/node/watch/fs.watch.test.ts
• test/js/third_party/esbuild/esbuild-child_process.test.ts

View test output

^{#a2ff5f6f03526acdd68b2f8977e3395522a39f67}

[github-actions]

❌ @jhmaster2000 6 files with test failures on bun-darwin-x64-baseline:

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

View test output

^{#a2ff5f6f03526acdd68b2f8977e3395522a39f67}