✨ Support whole-array OpenQASM copies

[simon1hofmann]

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Description

Support whole-array initialization (array[int, 2] b = a;) and assignment (b = a;) in the OpenQASM frontend. Source and destination must have matching shapes and element types, including widths. The source must be fully initialized. Copies use independent storage, preserve angle quantization, and support runtime updates and control flow. Self-assignment preserves the array.

Reuse memref.copy, fixed stack storage, and the QIR infrastructure from #2573. Copies remain compact in the emitted IR. The native QCO interpreter copies values without replacing storage shared with helper calls. Adaptive QIR handles residual copies; Base QIR accepts only programs whose unsupported storage and computation disappear during cleanup.

Stacked on #2574. Refs #2109; this is an intermediate slice and does not close the issue. Subarrays, ranges, concatenation, array outputs, and export of residual array storage remain follow-ups.

Validation

• At this PR boundary, all 203 frontend/emitter, 237 compiler, and 202 native QCO tests pass, including QC/QCO round trips and Adaptive QIR execution.
• Full-file C++ lint found no issues in this PR's changed files. Repository lint and diff-whitespace checks pass.
• Hosted CI for the pushed commits has not been checked.

Codex assisted with implementation, tests, documentation, and this description.

Checklist

• The pull request only contains commits that are focused and relevant to this change.
• I have added appropriate tests that cover the new/changed functionality.
• I have updated the documentation to reflect these changes.
• The changes follow the project's style guidelines and introduce no new warnings.
• The changes are fully tested and pass the CI checks.
• I have reviewed my own code changes.

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[codecov]

Codecov Report

❌ Patch coverage is 95.55556% with 2 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
mlir/lib/Dialect/QCO/Utils/DDFunctionality.cpp	80.0%	2 Missing ⚠️

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