ppc64: [baseline] preserve code_obj reg before C call

Change-Id: I78ef9bf817f32b8f2b96092ed9f77f223b2aa381
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3702975Reviewed-by: Milad Farazmand <mfarazma@redhat.com>
Commit-Queue: Junliang Yan <junyan@redhat.com>
Cr-Commit-Position: refs/heads/main@{#81160}

src/builtins/ppc/builtins-ppc.cc

@@ -212,6 +212,7 @@ void Generate_BaselineOrInterpreterEntry(MacroAssembler* masm,
              MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
   // Save the accumulator register, since it's clobbered by the below call.
   __ Push(kInterpreterAccumulatorRegister);
+  __ Push(code_obj);
   {
     Register arg_reg_1 = r3;
     Register arg_reg_2 = r4;
@@ -223,6 +224,7 @@ void Generate_BaselineOrInterpreterEntry(MacroAssembler* masm,
     __ PrepareCallCFunction(4, 0, ip);
     __ CallCFunction(get_baseline_pc, 3, 0);
   }
+  __ Pop(code_obj);
   __ AddS64(code_obj, code_obj, kReturnRegister0);
   __ Pop(kInterpreterAccumulatorRegister);