s390: [wasm-gc] Implement optional-depth rtts

Port 3a2ae154

Original Commit Message:

    As per the latest wasm-gc spec, rtts now have optional depth, with
    (rtt n type) <: (rtt type) for every depth n. Liftoff compilation
for
    type checks without depth are not supported yet.

R=manoskouk@chromium.org, joransiu@ca.ibm.com, junyan@redhat.com,
midawson@redhat.com, mfarazma@redhat.com
BUG=
LOG=N

Change-Id: Iba3d5184be1e69fae805873f832670ed33a41247
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2693326Reviewed-by: Milad Fa <mfarazma@redhat.com>
Commit-Queue: Junliang Yan <junyan@redhat.com>
Cr-Commit-Position: refs/heads/master@{#72718}

src/wasm/baseline/s390/liftoff-assembler-s390.h

@@ -639,6 +639,7 @@ void LiftoffAssembler::Spill(int offset, LiftoffRegister reg, ValueType type) {
     case ValueType::kOptRef:
     case ValueType::kRef:
     case ValueType::kRtt:
+    case ValueType::kRttWithDepth:
       StoreU64(reg.gp(), dst);
       break;
     case ValueType::kF32: