feat: faster, lazy-friendly runtime loading

[RomainMuller]

Instead of eagerly loading each type from the assemblies in order to annotate the constructors with jsii fully qualified type names (FQNs), leverage the jsii.rtti data that is injected by the jsii compiler since release 1.19.0.

This should make the jsii runtimes friendlier to large libraries that include lazy-loading provisions, such as the aws-cdk-lib.

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In addition to this, JSII_RUNTIME_PACKAGE_CACHE was flipped from opt-in to opt-out (set it to any value other than enabled to disable), and the @jsii/runtime entry point now sets --preserve-symlinks so that we can symbolically link packages from the cache instead of copying them around, which is significantly faster.

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Finally, the jsii kernel had not opted out of the assembly validation feature, which is redundant in the majority of scenarios, and is quite time-consuming (~500ms for aws-cdk-lib)... So also opting out, but allowing users to opt-back-in via an environment variable.

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Example on a "simple" repro via aws-cdk-lib:

Before:

[@jsii/kernel:timing] tar.extract(<redacted>/.venv-vanilla/lib/python3.11/site-packages/aws_cdk/_jsii/[email protected]) => <redacted>/jsii-kernel-Xxp43L/node_modules/aws-cdk-lib: 1.909s
[@jsii/kernel:timing] loadAssemblyFromPath(<redacted>/jsii-kernel-Xxp43L/node_modules/aws-cdk-lib): 383.8ms
[@jsii/kernel:timing] require(<redacted>/jsii-kernel-Xxp43L/node_modules/aws-cdk-lib): 630.081ms
[@jsii/kernel:timing] registerAssembly({ name: aws-cdk-lib, types: 10957 }): 8.452ms
[@jsii/kernel:timing] load({
  "name": "aws-cdk-lib",
  "version": "2.87.0",
  "tarball": "<redacted>/.venv-vanilla/lib/python3.11/site-packages/aws_cdk/_jsii/[email protected]",
  "api": "load"
}): 2.933s

After:

[@jsii/kernel:timing] tar.extract(<redacted>/.venv-lazy/lib/python3.11/site-packages/aws_cdk/_jsii/[email protected]) => <redacted>/jsii-kernel-eAOMah/node_modules/aws-cdk-lib: 12.247ms
[@jsii/kernel:timing] loadAssemblyFromPath(<redacted>/jsii-kernel-eAOMah/node_modules/aws-cdk-lib): 388.388ms
[@jsii/kernel:timing] require(<redacted>/jsii-kernel-eAOMah/node_modules/aws-cdk-lib/lazy-index.js): 132.801ms
[@jsii/kernel:timing] registerAssembly({ name: aws-cdk-lib, types: 10957 }): 0.009ms
[@jsii/kernel:timing] load({
  "name": "aws-cdk-lib",
  "version": "2.87.0",
  "tarball": "<redacted>/.venv-lazy/lib/python3.11/site-packages/aws_cdk/_jsii/[email protected]",
  "api": "load"
}): 537.449ms

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[mergify]

Thank you for contributing! ❤️ I will now look into making sure the PR is up-to-date, then proceed to try and merge it!

[mergify]

Merging (with squash)...