fix: Specialized ReshapedArray dispatch to resolve setindex! ambiguities

[shreyas-omkar]

Fix for #587

Summary

Resolves setindex! method ambiguities occurring when using ReshapedArray views of GPU-backed arrays.

Issue

The ambiguity was caused by a dispatch tie between the general WrappedGPUArray union method and the specialized ReshapedArray constructor. This PR breaks that tie by providing specialized _unsafe_setindex! methods for IndexLinear and IndexCartesian.

By specifying the concrete IndexStyle subtypes, these methods provide a narrower dispatch scope, ensuring Julia selects the correct vectorized path for reshaped views.

Changes

• src/host/indexing.jl: Added specialized dispatch methods for ReshapedArray to resolve ambiguities.
• test/testsuite/indexing.jl: Added a combinatorial test suite to verify the fix across various nested wrapper types (views, permutations, and reinterpreted arrays).

Verification

• Confirmed fix resolves MethodError in the reported minimal working example.
• Verified data parity between CPU and GPU results using compare().
• Successfully ran the new indexing combinatorial test suite on ROCArray and JLArray.