✨ Support runtime OpenQASM array size queries

[simon1hofmann]

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Description

Support sizeof on runtime-sized classical array slices, such as sizeof(a[start:step:stop]). The result is a runtime uint; queries with known extents still fold to constants, including zero-length dimensions and fixed dimensions beside runtime-sized ones.

• Reuse the existing inclusive range calculation and runtime bounds/step preconditions.
• Do not read array elements or create array copies or subviews. The queried array need not be initialized.
• Support nested queries and use in arithmetic, conditions, gate parameters, and loop bodies/bounds. Keep the queried dimension a compile-time integer.
• Diagnose runtime size queries in constant-only contexts, including const initializers and fixed array/type widths.

Stacked on #2584. No new dependencies or dialect operations. Refs #2109; this is an intermediate slice and does not close the issue.

Validation

• At this PR boundary, all 210 frontend/emitter, 239 compiler, 204 native QCO, and 219 QC translation 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 99.01961% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
mlir/lib/Target/OpenQASM/OpenQASMSemantics.cpp	98.5%	1 Missing ⚠️

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