Merge pull request #9980 from Pokechu22/dsp-disassembly-lsr-asr

DSPDisassembler: Fix LSR/ASR formatting

Source/Core/Core/DSP/DSPDisassembler.cpp

@@ -105,8 +105,9 @@ std::string DSPDisassembler::DisassembleParameters(const DSPOPCTemplate& opc, u1
         // LSL, LSR, ASL, ASR
         if (opc.params[j].mask == 0x003f)
         {
-          // 6-bit sign extension
-          buf += fmt::format("#{}", (val & 0x20) != 0 ? (val | 0xFFFFFFC0) : val);
+          // Left and right shifts function essentially as a single shift by a 7-bit signed value,
+          // but are split into two intructions for clarity.
+          buf += fmt::format("#{}", (val & 0x20) != 0 ? (64 - val) : val);
         }
         else
         {