ppc: [liftoff] fix fp64 and simd handling

Change-Id: I3d75f2e5fdb9c43b4795dee80377725318ee271f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3075122Reviewed-by: Milad Fa <mfarazma@redhat.com>
Commit-Queue: Junliang Yan <junyan@redhat.com>
Cr-Commit-Position: refs/heads/master@{#76120}

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

@@ -156,7 +156,7 @@ void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
     case kF64: {
       UseScratchRegisterScope temps(this);
       Register scratch = temps.Acquire();
-      mov(scratch, Operand(value.to_f32_boxed().get_scalar()));
+      mov(scratch, Operand(value.to_f64_boxed().get_scalar()));
       MovInt64ToDouble(reg.fp(), scratch);
       break;
     }
@@ -322,6 +322,8 @@ void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
       }
       break;
     case LoadType::kS128Load:
+      bailout(kUnsupportedArchitecture, "SIMD");
+      break;
     default:
       UNREACHABLE();
   }