swift

581cfcd7 - [sil] Add @inferredImmutable flag to SILFunctionArgument for captured boxes

[sil] Add @inferredImmutable flag to SILFunctionArgument for captured boxes Introduce a new optional inferred-immutable flag on SILFunctionArgument to mark closure-captured box parameters that are never written to despite being mutable. This flag will enable in future commits: - Marking captured mutable boxes as immutable when interprocedural analysis proves they are never modified - Treating these captures as Sendable when they contain Sendable types - Improving region-based isolation analysis for concurrent code This complements the inferred-immutable flag on alloc_box by allowing immutability information to flow through closure boundaries.