Add remaining high-priority rewriter extended tests

[gramalingam]

Summary

Add 22 extended tests across 8 test files covering the remaining high-priority gaps identified in the rewriter test gap analysis.

New test files

File	Tests	Rule module
_cast_constant_of_shape_extended_test.py	5	_cast_constant_of_shape
_fuse_conv_affine_extended_test.py	5	_fuse_conv_affine
_redundant_scatter_nd_extended_test.py	3	_redundant_scatter_nd
_rotary_embedding_extended_test.py (rules/fusion)	3	PartialRotaryEmbedding23Fusion
_gqa_extended_test.py (rules/fusion)	2	GroupQueryAttentionFusion
gqa_extended_test.py (ort_fusions)	1	gqa ORT fusion
gqa_packed_qkv_extended_test.py (ort_fusions)	1	gqa packed QKV
cos_sin_cache_extended_test.py (ort_fusions)	2	cos_sin_cache

Key patterns used

• @script() API with op.Constant(value=...) for embedded constants
• Symbolic dimensions ("B", "S") where appropriate
• Numerical validation via ORT or ONNX reference implementation
• Negative tests: non-constant operands, padded convolutions, missing prerequisites, mismatched boundaries
• Script generator with traced-if for clean negative test model construction

Modified existing file

• _rotary_embedding_models.py: Added _make_partial_rotary_script(mismatched) generator for clean negative test construction

Follow-up to PR #2896.

[codecov]

Codecov Report

❌ Patch coverage is 65.19231% with 181 lines in your changes missing coverage. Please review.
✅ Project coverage is 72.48%. Comparing base (1911741) to head (fe3e63b).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...nxscript/rewriter/ort_fusions/gqa_extended_test.py	55.12%	34 Missing and 1 partial ⚠️
...script/rewriter/rules/fusion/_gqa_extended_test.py	50.70%	33 Missing and 2 partials ⚠️
...ewriter/ort_fusions/cos_sin_cache_extended_test.py	50.72%	33 Missing and 1 partial ⚠️
...er/rules/common/_fuse_conv_affine_extended_test.py	66.29%	29 Missing and 1 partial ⚠️
...script/rewriter/models/_rotary_embedding_models.py	14.81%	23 Missing ⚠️
...ules/common/_redundant_scatter_nd_extended_test.py	85.24%	8 Missing and 1 partial ⚠️
...writer/ort_fusions/gqa_packed_qkv_extended_test.py	77.41%	6 Missing and 1 partial ⚠️
...er/rules/fusion/_rotary_embedding_extended_test.py	89.83%	3 Missing and 3 partials ⚠️
...es/common/_cast_constant_of_shape_extended_test.py	94.28%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2899      +/-   ##
==========================================
- Coverage   72.51%   72.48%   -0.04%     
==========================================
  Files         250      258       +8     
  Lines       30955    31475     +520     
  Branches     2960     2973      +13     
==========================================
+ Hits        22448    22815     +367     
- Misses       7504     7650     +146     
- Partials     1003     1010       +7     

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[Copilot]

Pull request overview

This PR expands the ONNXScript rewriter “extended” test suite to cover additional high-priority fusion/rewrite gaps, and introduces a small model-generator helper to build cleaner negative rotary-embedding cases.

Changes:

• Added new extended test modules for multiple rewriter rules (fusion, common, and ort_fusions).
• Added negative/positive scenarios including boundary mismatches and prerequisite-missing cases.
• Extended the rotary-embedding model helpers with a script generator for partial rotary patterns.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
onnxscript/rewriter/rules/fusion/_rotary_embedding_extended_test.py	Adds extended tests for PartialRotaryEmbedding23 (positive + negative cases).
onnxscript/rewriter/rules/fusion/_gqa_extended_test.py	Adds extended tests for fusion GQA rule (negative wrong-group + a positive alt config).
onnxscript/rewriter/rules/common/_redundant_scatter_nd_extended_test.py	Adds extended tests for redundant ScatterND elimination.
onnxscript/rewriter/rules/common/_fuse_conv_affine_extended_test.py	Adds extended tests for Conv/Affine fusion rules (positive + multiple negatives).
onnxscript/rewriter/rules/common/_cast_constant_of_shape_extended_test.py	Adds extended dtype-coverage tests for Cast+ConstantOfShape fusion.
onnxscript/rewriter/ort_fusions/gqa_packed_qkv_extended_test.py	Adds extended negative test for packed-QKV GQA fusion.
onnxscript/rewriter/ort_fusions/gqa_extended_test.py	Adds an extended negative test for ort_fusions GQA (no RotaryEmbedding prerequisite).
onnxscript/rewriter/ort_fusions/cos_sin_cache_extended_test.py	Adds extended tests for cos/sin cache fusion (dynamic inv_freq negative + sanity positive).
onnxscript/rewriter/models/_rotary_embedding_models.py	Adds _make_partial_rotary_script(mismatched=...) generator to support negative test construction.