target/ppc: Fix lqarx to set cpu_reserve

lqarx does not set cpu_reserve, which causes stqcx. to never succeed.

Cc: qemu-stable@nongnu.org
Fixes: 94bf265 ("target/ppc: Use atomic load for LQ and LQARX")
Fixes: 57b38ff ("target/ppc: Use tcg_gen_qemu_{ld,st}_i128 for LQARX, LQ, STQ")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230605025445.161932-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

target/ppc/translate.c

@@ -3765,6 +3765,7 @@ static void gen_lqarx(DisasContext *ctx)
     tcg_gen_qemu_ld_i128(t16, EA, ctx->mem_idx, DEF_MEMOP(MO_128 | MO_ALIGN));
     tcg_gen_extr_i128_i64(lo, hi, t16);
 
+    tcg_gen_mov_tl(cpu_reserve, EA);
     tcg_gen_st_tl(hi, cpu_env, offsetof(CPUPPCState, reserve_val));
     tcg_gen_st_tl(lo, cpu_env, offsetof(CPUPPCState, reserve_val2));
 }