[compiler] Handle sequential optionals

[everettbu]

Mirror of facebook/react#35673
Original author: josephsavona

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The previous PR (#35606) handled maybe-throw terminals within value blocks, and the changes there also made BuildReactiveFunction able to handle sequential optionals. However, CollectOptionalChainDependencies doesn't yet handle sequential value blocks, like foo(a?.b, b?.c) ?? {}. This PR fixes the remaining case, which means we should no longer have arbitrary limitations around value blocks.

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Greptile Overview

Greptile Summary

This PR extends the React compiler's ability to handle sequential optional chains in value blocks. Previously, CollectOptionalChainDependencies could not handle cases where multiple optional chains or other value blocks (logical, ternary) appeared as function arguments, such as foo(a?.b, b?.c) ?? {}.

The implementation adds two new helper functions:

• findOptionalTestBlock: Traverses through intermediate value blocks and nested terminals to find the test block for an optional chain
• traverseValueBlock: Recursively processes value blocks to collect nested optional chains within logical, ternary, or sequence expressions

The fix resolves a previous TODO error ("Unexpected terminal kind optional for optional fallthrough block") that occurred when the compiler encountered sequential optionals. The PR includes comprehensive test coverage for various scenarios including multiple optional arguments, nested calls, logical operators, ternaries, and combinations thereof.

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The changes are well-structured with clear recursive helpers that follow existing patterns in the codebase. The fix resolves a known limitation (previously marked as TODO), includes extensive test coverage for edge cases, and maintains backward compatibility.
• No files require special attention

Important Files Changed

Filename	Overview
compiler/packages/babel-plugin-react-compiler/src/HIR/CollectOptionalChainDependencies.ts	Added findOptionalTestBlock and traverseValueBlock helper functions to handle sequential optional chains in value blocks like foo(a?.b, b?.c) ?? {}
compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/error.todo-optional-call-chain-in-optional.expect.md	Deleted error test - this case now compiles successfully after the fix
compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/optional-call-chain-in-optional.expect.md	New passing test for createArray(value?.x, value?.y)?.join(', ') pattern that previously threw a TODO error
compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/optional-call-with-multiple-optional-args.expect.md	New test validating compilation of foo(a?.value, b?.value)?.result with multiple optional arguments

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