[Bug] [Relay] [Keras]relay.concatenate requires all tensors have the same shape on non-concatenating axes

[jikechao]

For the input:

keras.layers.Concatenate(axis=2) 
input_shape1 =[1, 1, 4, 5]
input_shape2 = [1, 1, 8, 5]

The two input tensors have the same shape in non-concatenating axes(i.e., axis=2).

However, TVM threw an unexpected exception:

Traceback (most recent call last):
  8: TVMFuncCall
  7: tvm::runtime::PackedFuncObj::Extractor<tvm::runtime::PackedFuncSubObj<tvm::runtime::TypedPackedFunc<tvm::IRModule (tvm::transform::Pass, tvm::IRModule)>::AssignTypedLambda<tvm::transform::$_6>(tvm::transform::$_6, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)::{lambda(tvm::runtime::TVMArgs const&, tvm::runtime::TVMRetValue*)#1}> >::Call(tvm::runtime::PackedFuncObj const*, tvm::runtime::TVMArgs, tvm::runtime::TVMRetValue*)
  6: tvm::transform::Pass::operator()(tvm::IRModule) const
  5: tvm::transform::Pass::operator()(tvm::IRModule, tvm::transform::PassContext const&) const
  4: tvm::transform::ModulePassNode::operator()(tvm::IRModule, tvm::transform::PassContext const&) const
  3: tvm::runtime::PackedFuncObj::Extractor<tvm::runtime::PackedFuncSubObj<tvm::runtime::TypedPackedFunc<tvm::IRModule (tvm::IRModule, tvm::transform::PassContext)>::AssignTypedLambda<tvm::relay::transform::InferType()::$_2>(tvm::relay::transform::InferType()::$_2)::{lambda(tvm::runtime::TVMArgs const&, tvm::runtime::TVMRetValue*)#1}> >::Call(tvm::runtime::PackedFuncObj const*, tvm::runtime::TVMArgs, tvm::runtime::TVMRetValue*)
  2: tvm::relay::TypeInferencer::Infer(tvm::GlobalVar, tvm::relay::Function)
  1: tvm::relay::TypeSolver::Solve()
  0: _ZN3tvm7runtime6detail
  File "/workplace/software/tvm/tvm/src/relay/analysis/type_solver.cc", line 643
TVMError: 
---------------------------------------------------------------
An error occurred during the execution of TVM.
For more information, please see: https://tvm.apache.org/docs/errors.html
---------------------------------------------------------------
  Check failed: (false) is false: relay.concatenate requires all tensors have the same shape on non-concatenating axes
``


### Triage

* relay:analysis
* needs-triage


cc @shingjan