Upstream sharpened GraphIR

[ganler]

• Sharpened GraphIR to support various mutations and multiple return values.
  • SSA (ack LLVM IR and ONNX)
  • Allow multiple return values (ack ONNX) but bound to instructions. (return value identifier is ${instruction_id}.{index}).
  • Mutation: IR-safety oriented mutation APIs: 1) replace use; 2) remove unused; 3) insert; so that given a valid GraphIR each operation should return an also valid GraphIR;
  • IR Repair: allow partial validity: the topology order and use-def chain of a GraphIR can be broken but later fixed by GraphIR.wellform_repair. This is designed for some longer-context IR mutation;
  • Integration of GraphIR to all existing pipelines is still under development in experimental repo/branches and will be upstreamed once found steady.
• Other minor improvements: add a few data type supports (still not used in generation tho) to allow NNReduce to debug quantized models.

[ganler]

The CI failure is due to two bugs in TVM-10. Sent a PR in apache/tvm#13448.

Maybe type tester should be isolated in individual processes for being able to catch segfaults.

[ganler]

Temporarily bypassed with downgrading the CI requirements to tvm-0.9.0.