buffer_queue: Make reference parameter of SetPreallocatedBuffer const

This is simply copied by value, so there's no need to make it a
modifiable reference.

While we're at it, make the names of the parameters match its
definition.

src/core/hle/kernel/hle_ipc.cpp

@@ -201,7 +201,7 @@ ResultCode HLERequestContext::PopulateFromIncomingCommandBuffer(u32_le* src_cmdb
     return RESULT_SUCCESS;
 }
 
-ResultCode HLERequestContext::WriteToOutgoingCommandBuffer(Thread& thread) {
+ResultCode HLERequestContext::WriteToOutgoingCommandBuffer(const Thread& thread) {
     std::array<u32, IPC::COMMAND_BUFFER_LENGTH> dst_cmdbuf;
     Memory::ReadBlock(*thread.owner_process, thread.GetTLSAddress(), dst_cmdbuf.data(),
                       dst_cmdbuf.size() * sizeof(u32));

src/core/hle/kernel/hle_ipc.h

@@ -132,7 +132,7 @@ public:
     ResultCode PopulateFromIncomingCommandBuffer(u32_le* src_cmdbuf, Process& src_process,
                                                  HandleTable& src_table);
     /// Writes data from this context back to the requesting process/thread.
-    ResultCode WriteToOutgoingCommandBuffer(Thread& thread);
+    ResultCode WriteToOutgoingCommandBuffer(const Thread& thread);
 
     u32_le GetCommand() const {
         return command;

src/core/hle/service/nvflinger/buffer_queue.cpp

@@ -16,7 +16,7 @@ BufferQueue::BufferQueue(u32 id, u64 layer_id) : id(id), layer_id(layer_id) {
         Kernel::Event::Create(Kernel::ResetType::Sticky, "BufferQueue NativeHandle");
 }
 
-void BufferQueue::SetPreallocatedBuffer(u32 slot, IGBPBuffer& igbp_buffer) {
+void BufferQueue::SetPreallocatedBuffer(u32 slot, const IGBPBuffer& igbp_buffer) {
     Buffer buffer{};
     buffer.slot = slot;
     buffer.igbp_buffer = igbp_buffer;

src/core/hle/service/nvflinger/buffer_queue.h

@@ -72,7 +72,7 @@ public:
         MathUtil::Rectangle<int> crop_rect;
     };
 
-    void SetPreallocatedBuffer(u32 slot, IGBPBuffer& buffer);
+    void SetPreallocatedBuffer(u32 slot, const IGBPBuffer& igbp_buffer);
     boost::optional<u32> DequeueBuffer(u32 width, u32 height);
     const IGBPBuffer& RequestBuffer(u32 slot) const;
     void QueueBuffer(u32 slot, BufferTransformFlags transform,

src/video_core/renderer_opengl/gl_shader_decompiler.cpp

@@ -657,17 +657,16 @@ private:
      * @param instr Instruction to generate the if condition for.
      * @returns string containing the predicate condition.
      */
-    std::string GetPredicateCondition(u64 index, bool negate) {
+    std::string GetPredicateCondition(u64 index, bool negate) const {
         using Tegra::Shader::Pred;
         std::string variable;
 
         // Index 7 is used as an 'Always True' condition.
-        if (index == static_cast<u64>(Pred::UnusedIndex)) {
+        if (index == static_cast<u64>(Pred::UnusedIndex))
             variable = "true";
-        } else {
+        else
             variable = 'p' + std::to_string(index) + '_' + suffix;
-            declr_predicates.insert(variable);
-        }
+
         if (negate) {
             return "!(" + variable + ')';
         }