[LLVM] Fix JIT unknown reloc issue for case of RISCV

[cbalint13]

This fixes the issue described in #17916

---

• Fall to a standard ORCJIT linker (from RTDyldLinker, introduced by MSWIN case), but still cope with COFF cases.
• Incorporates #17853, that prior info also allows parser simplification, to just read all infos from LLVM side.

---

The basic relax demo now runs fine, tested with llvm = {19,20}:

$ git diff docs/get_started/tutorials/quick_start.py
{...}
-target = tvm.target.Target("llvm")
+target = tvm.target.Target("llvm -mattr=+m,+a,+f,+d,+zfh,+v,+c")
{...}

$ python3 docs/get_started/tutorials/quick_start.py
# from tvm.script import ir as I
# from tvm.script import relax as R

@I.ir_module
class Module:
    @R.function
    def forward(x: R.Tensor((1, 784), dtype="float32"), fc1_weight: R.Tensor((256, 784), dtype="float32"), 
fc1_bias: R.Tensor((256,), dtype="float32"), fc2_weight: R.Tensor((10, 256), dtype="float32"),
 fc2_bias: R.Tensor((10,), dtype="float32")) -> R.Tensor((1, 10), dtype="float32"):
        R.func_attr({"num_input": 1})
        with R.dataflow():
            permute_dims: R.Tensor((784, 256), dtype="float32") = R.permute_dims(fc1_weight, axes=None)
            matmul: R.Tensor((1, 256), dtype="float32") = R.matmul(x, permute_dims, out_dtype="void")
            add: R.Tensor((1, 256), dtype="float32") = R.add(matmul, fc1_bias)
            relu: R.Tensor((1, 256), dtype="float32") = R.nn.relu(add)
            permute_dims1: R.Tensor((256, 10), dtype="float32") = R.permute_dims(fc2_weight, axes=None)
            matmul1: R.Tensor((1, 10), dtype="float32") = R.matmul(relu, permute_dims1, out_dtype="void")
            add1: R.Tensor((1, 10), dtype="float32") = R.add(matmul1, fc2_bias)
            gv: R.Tensor((1, 10), dtype="float32") = add1
            R.output(gv)
        return gv

[[25018.53  25440.596 24398.615 22915.344 25457.54  25424.28  25661.27
  24288.602 25659.234 23134.854]]

$ rpm -q llvm-devel
llvm-devel-20.1.2-3.fc42.riscv64

$ uname -a
Linux lpi3a 6.6.87-200.spacemit_bl2.1.fc41.riscv64 #1 SMP PREEMPT_DYNAMIC {..} riscv64 GNU/Linux

[cbalint13]

cc @Hzfengsy @Lunderberg @mshr-h
cc @tqchen