Test-only. Reloads this library from assetName's bytes while keeping
this library's identity and registry key. Production hot reload always
re-fetches the original asset path via reinitialize; this hook lets
tests simulate an edited bundle by swapping in a different fixture.
Reparses bytes into this library in place, preserving its identity so
any Shaders already handed out keep working (they are mutated and
marked dirty so the next pipeline build re-registers them). The
counterpart to reinitialize for a fromBytes library, which has no
asset path to re-fetch. Use it to swap in a recompiled shader bundle.
Loads a ShaderLibrary directly from a shader bundle's bytes (the
contents of a .shaderbundle compiled by impellerc), rather than from a
bundled asset. This suits shader bundles produced or fetched at runtime,
which have no entry in the asset manifest that fromAsset resolves.
Re-fetches assetKey through the asset manager and reparses it into
the cached ShaderLibrary for that key, marking each shader dirty so
the next pipeline build evicts and re-registers it. The primary caller
is the ext.ui.gpu.reinitializeShaderLibrary service extension driving
hot reload from flutter_tools; tests may also call this directly.
No-ops if no library has been loaded for assetKey.
