[loong64][mips] Remove the Dummy interface descriptor

Port commit 4ae5a813

Change-Id: I194b424996d9f2427272fdd0510b6a464c4e07d0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3602233
Auto-Submit: Yu Liu <liuyu@loongson.cn>
Reviewed-by: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Cr-Commit-Position: refs/heads/main@{#80102}

src/codegen/loong64/interface-descriptors-loong64-inl.h

@@ -229,8 +229,7 @@ constexpr auto ConstructStubDescriptor::registers() {
   // a1: target
   // a3: new target
   // a0: number of arguments
-  // a2: allocation site or undefined
-  return RegisterArray(a1, a3, a0, a2);
+  return RegisterArray(a1, a3, a0);
 }
 
 // static

src/codegen/mips/interface-descriptors-mips-inl.h

@@ -228,8 +228,7 @@ constexpr auto ConstructStubDescriptor::registers() {
   // a1: target
   // a3: new target
   // a0: number of arguments
-  // a2: allocation site or undefined
-  return RegisterArray(a1, a3, a0, a2);
+  return RegisterArray(a1, a3, a0);
 }
 
 // static

src/codegen/mips64/interface-descriptors-mips64-inl.h

@@ -229,8 +229,7 @@ constexpr auto ConstructStubDescriptor::registers() {
   // a1: target
   // a3: new target
   // a0: number of arguments
-  // a2: allocation site or undefined
-  return RegisterArray(a1, a3, a0, a2);
+  return RegisterArray(a1, a3, a0);
 }
 
 // static