s390x: [liftoff] implement emit_smi_check

Change-Id: Icb0d165c97e4a08d4111dd1ad0e1402f4a28746f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2821634Reviewed-by: Milad Fa <mfarazma@redhat.com>
Commit-Queue: Junliang Yan <junyan@redhat.com>
Cr-Commit-Position: refs/heads/master@{#73921}

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

@@ -2124,7 +2124,9 @@ bool LiftoffAssembler::emit_select(LiftoffRegister dst, Register condition,
 
 void LiftoffAssembler::emit_smi_check(Register obj, Label* target,
                                       SmiCheckMode mode) {
-  bailout(kUnsupportedArchitecture, "emit_smi_check");
+  TestIfSmi(obj);
+  Condition condition = mode == kJumpOnSmi ? eq : ne;
+  b(condition, target);  // branch if SMI
 }
 
 void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,