[quant][pt2] Handle constant conv args in prepare QAT fusion (#100525)
Summary: Previously, we would only match and replace conv + BN
patterns with default constant args for conv (stride, padding,
dilation etc.). If the user sets one of these args to values
that are different from the default, we would simply not fuse
the pattern. This is due to a limitation in the subgraph
rewriter: see https://github.com/pytorch/pytorch/issues/100419.
This commit works around the above limitation by first
configuring the subgraph rewriter to ignore literals when
matching, and then manually copy over the constant args to the
new subgraph after `replace_pattern`.
Test Plan:
python test/test_quantization.py TestQuantizePT2E.test_prepare_qat_conv_bn_fusion_constant_args
Reviewers: jerryzh168, kimishpatel
Differential Revision: [D45515437](https://our.internmc.facebook.com/intern/diff/D45515437)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100525
Approved by: https://github.com/jerryzh168
