[mips] Fix error in LeaveExitFrame

Port e5a53a4c

Bug: v8:11767
Change-Id: I4214f844932c4b7b4f91c3c983cd9228c7975891
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2914772
Auto-Submit: Liu yu <liuyu@loongson.cn>
Reviewed-by: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Cr-Commit-Position: refs/heads/master@{#74722}

src/codegen/mips64/macro-assembler-mips64.cc

@@ -5449,11 +5449,12 @@ void MacroAssembler::LeaveExitFrame(bool save_doubles, Register argument_count,
      ExternalReference::Create(IsolateAddressId::kContextAddress, isolate()));
   Ld(cp, MemOperand(t8));
 
-#ifdef DEBUG
-  li(t8,
-     ExternalReference::Create(IsolateAddressId::kContextAddress, isolate()));
-  Sd(a3, MemOperand(t8));
-#endif
+  if (FLAG_debug_code) {
+    UseScratchRegisterScope temp(this);
+    Register scratch = temp.Acquire();
+    li(scratch, Operand(Context::kInvalidContext));
+    Sd(scratch, MemOperand(t8));
+  }
 
   // Pop the arguments, restore registers, and return.
   mov(sp, fp);  // Respect ABI stack constraint.