ppc: [liftoff] implement smi_check

Change-Id: Ifc75747a179486b6fe173c2d34f72f66c1918d88
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3124813Reviewed-by: Milad Fa <mfarazma@redhat.com>
Commit-Queue: Junliang Yan <junyan@redhat.com>
Cr-Commit-Position: refs/heads/main@{#76544}

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

@@ -1222,7 +1222,9 @@ void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
 
 void LiftoffAssembler::emit_smi_check(Register obj, Label* target,
                                       SmiCheckMode mode) {
-  bailout(kUnsupportedArchitecture, "emit_smi_check");
+  TestIfSmi(obj, r0);
+  Condition condition = mode == kJumpOnSmi ? eq : ne;
+  b(condition, target, cr0);  // branch if SMI
 }
 
 void LiftoffAssembler::LoadLane(LiftoffRegister dst, LiftoffRegister src,