perf(@angular/build): read rendered module length once per module in chunk optimizer

When converting the chunk optimizer output into an esbuild-compatible metafile, the
rendered length of each module was read inside the loop over the module's original
inputs. The `renderedLength` property of a rolldown rendered module is a lazy getter
that transfers the full module code from native memory on every access. Since each
module in this pass is an entire esbuild output chunk, a main chunk of 17 MB with
3,588 inputs resulted in roughly 62 GB of string copies and around 150 seconds spent in
`bundleOutputToEsbuildMetafile`, while the rolldown bundling itself took 3 seconds.

Read the rendered length once per module before iterating its inputs. The generated
metafile is unchanged. On the affected application the `OPTIMIZE_CHUNKS` phase drops
from 179 seconds to 4 seconds and the total production build from 234 to 55 seconds.

Fixes #34044

Author: roman-garcia

packages/angular/build/src/builders/application/chunk-optimizer.ts

@@ -113,11 +113,16 @@ function bundleOutputToEsbuildMetafile(
           continue;
         }
 
+        // Read the rendered length once per module. The value is a lazy getter on the bundler's
+        // rendered module object that transfers the entire module code from native memory on each
+        // access, which is prohibitively expensive when repeated for every input of a large chunk.
+        const { renderedLength } = renderedModule;
+
         for (const [originalInputPath, originalInputInfo] of Object.entries(
           originalOutputEntry.inputs,
         )) {
           const proportion = originalInputInfo.bytesInOutput / totalOriginalBytesInModule;
-          const newBytesInOutput = Math.floor(renderedModule.renderedLength * proportion);
+          const newBytesInOutput = Math.floor(renderedLength * proportion);
 
           const existing = newOutputInputs[originalInputPath];
           if (existing) {