ipc_helpers: add PopPID; remove PushCurrentPIDHandle

It doesn't make sense for a service to tell its own PID to a client, and there is no such use case. Also the name "handle" is misleading as the PID is not a handle

src/core/hle/ipc_helpers.h

@@ -128,8 +128,6 @@ public:
     template <typename... O>
     void PushMoveObjects(Kernel::SharedPtr<O>... pointers);
 
-    void PushCurrentPIDHandle();
-
     [[deprecated]] void PushStaticBuffer(VAddr buffer_vaddr, size_t size, u8 buffer_id);
     void PushStaticBuffer(const std::vector<u8>& buffer, u8 buffer_id);
 
@@ -208,11 +206,6 @@ inline void RequestBuilder::PushMoveObjects(Kernel::SharedPtr<O>... pointers) {
     PushMoveHandles(context->AddOutgoingHandle(std::move(pointers))...);
 }
 
-inline void RequestBuilder::PushCurrentPIDHandle() {
-    Push(CallingPidDesc());
-    Push(u32(0));
-}
-
 inline void RequestBuilder::PushStaticBuffer(VAddr buffer_vaddr, size_t size, u8 buffer_id) {
     Push(StaticBufferDesc(size, buffer_id));
     Push(buffer_vaddr);
@@ -338,6 +331,8 @@ public:
         std::tie(pointers...) = PopObjects<T...>();
     }
 
+    u32 PopPID();
+
     /**
      * @brief Pops the static buffer vaddr
      * @return                  The virtual address of the buffer
@@ -507,6 +502,11 @@ inline std::tuple<Kernel::SharedPtr<T>...> RequestParser::PopObjects() {
                                           std::index_sequence_for<T...>{});
 }
 
+inline u32 RequestParser::PopPID() {
+    ASSERT(Pop<u32>() == static_cast<u32>(DescriptorType::CallingPid));
+    return Pop<u32>();
+}
+
 inline VAddr RequestParser::PopStaticBuffer(size_t* data_size) {
     const u32 sbuffer_descriptor = Pop<u32>();
     StaticBufferDescInfo bufferInfo{sbuffer_descriptor};