[NupharEP] symbolic_shape_infer improvements (#2299)
- Improves symbolic shape inference in following ways:
1. Extend suggested merge to map to literals with --auto_merge. For example, MatMul of ['ax1', 'ax2'] x [128, 256] would now map 'ax2' to 128
2. Add --int_max option to simplify computations like Min(100000, 'dim') to be 'dim'. This helps ops like Slice to generate correct shape, i.e. start=0, end=Min(100000, dim - 2) on dim. It was previously treated as equal, since sympy cannot determine Min(100000, dim - 2) < dim.
- Fix a bug in create_shared script on Windows, that AOT dll is not generated because of failure in link, when there are too many obj files
- Fix a bug for Split since TOPI does not support split on symbolic dimension.
- Some build warning fixes for NupharEP.
