Missing `[compile]` and `[link]` annotations in some settings

Some settings in `settings.js` have neither `[compile]`, `[link]` or `[compile+link]` annotations. These are particularly useful for https://emsettings.surma.technology/, so decided to report them for tracking:

- [ ] `SUPPORT_BIG_ENDIAN`
- [ ] `GL_EXPLICIT_UNIFORM_LOCATION`
- [ ] `GL_EXPLICIT_UNIFORM_BINDING`
- [ ] `GL_WORKAROUND_SAFARI_GETCONTEXT_BUG`
- [ ] `EXPORT_EXCEPTION_HANDLING_HELPERS`
- [ ] `EXTRA_EXPORTED_RUNTIME_METHODS`
- [ ] `IN_TEST_HARNESS`
- [ ] `LOAD_SOURCE_MAP`
- [ ] `WASM2C_SANDBOXING`
- [ ] `AUTOLOAD_DYLIBS`
- [ ] `ALLOW_UNIMPLEMENTED_SYSCALLS`
- [ ] `POLYFILL`
- [ ] `LEGACY_RUNTIME`
- [ ] `LEGACY_SETTINGS`

cc @surma @sbc100