[Bug] [Relax] Segmentation fault when executeing inference for the IR with branch in the runtime

[jikechao]

Actual behavior

...
[09:37:39] /software/tvm/src/runtime/relax_vm/vm.cc:735: 
  pc = 21, execute: vm.builtin.alloc_tensor
Segmentation fault (core dumped)

Steps to reproduce

import tvm
from tvm import relax
import numpy as np
from tvm.script import ir as I
from tvm.script import tir as T
from tvm.script import relax as R

@I.ir_module
class Module:

    @R.function
    def main(cond: R.Tensor((), dtype="bool"), x: R.Tensor((1,), dtype="float32")) -> R.Tensor((4703,), dtype="float32"):
        cls = Module
        if cond:
            gv = R.add(x,x)
            gv1 = R.add(x,x)
            y_then = R.multiply(gv,gv1)
            y: R.Tensor((1,), dtype="float32") = y_then
        else:
            gv3 = R.multiply(x,x)
            gv4 = R.multiply(x,x)
            y_else = R.add(gv3,gv4)
            y: R.Tensor((1,), dtype="float32") = y_else
        return y

mod = Module

input_0 = tvm.nd.array(np.bool_(False))
input_1 = tvm.nd.array(np.random.random([1]).astype('float32'))
ex = relax.build(mod, target='llvm')
vm = relax.VirtualMachine(ex, tvm.cpu())
mod_outputs = vm['main'](input_0,input_1)  # segfault!

cc @junrushao