Skip loading unknown XF registers in the FIFO player

This avoids some warnings, which were originally fixed by ignoring loads with a value of zero (see 636bedb207 / #3242).

Note that FifoCI will report some changes, but only on the first frame; these seem to be timing related as they don't happen if a different write is used to replace skipped ones.

Source/Core/Core/FifoPlayer/FifoPlayer.cpp

@@ -491,7 +491,10 @@ void FifoPlayer::LoadRegisters()
 
   regs = m_File->GetXFRegs();
   for (int i = 0; i < FifoDataFile::XF_REGS_SIZE; ++i)
-    LoadXFReg(i, regs[i]);
+  {
+    if (ShouldLoadXF(i))
+      LoadXFReg(i, regs[i]);
+  }
 }
 
 void FifoPlayer::LoadTextureMemory()
@@ -571,6 +574,16 @@ bool FifoPlayer::ShouldLoadBP(u8 address)
   }
 }
 
+bool FifoPlayer::ShouldLoadXF(u8 reg)
+{
+  // Ignore unknown addresses
+  u16 address = reg + 0x1000;
+  return !(address == XFMEM_UNKNOWN_1007 ||
+           (address >= XFMEM_UNKNOWN_GROUP_1_START && address <= XFMEM_UNKNOWN_GROUP_1_END) ||
+           (address >= XFMEM_UNKNOWN_GROUP_2_START && address <= XFMEM_UNKNOWN_GROUP_2_END) ||
+           (address >= XFMEM_UNKNOWN_GROUP_3_START && address <= XFMEM_UNKNOWN_GROUP_3_END));
+}
+
 bool FifoPlayer::IsIdleSet()
 {
   CommandProcessor::UCPStatusReg status =

Source/Core/Core/FifoPlayer/FifoPlayer.h

@@ -134,6 +134,7 @@ private:
   void LoadXFMem16(u16 address, const u32* data);
 
   bool ShouldLoadBP(u8 address);
+  bool ShouldLoadXF(u8 address);
 
   static bool IsIdleSet();
   static bool IsHighWatermarkSet();