common: Change semantics of UNREACHABLE to unconditionally crash

src/video_core/command_classes/codecs/codec.cpp

@@ -224,7 +224,7 @@ void Codec::Decode() {
             vp9_hidden_frame = vp9_decoder->WasFrameHidden();
             return vp9_decoder->GetFrameBytes();
         default:
-            UNREACHABLE();
+            ASSERT(false);
             return std::vector<u8>{};
         }
     }();

src/video_core/command_classes/vic.cpp

@@ -228,7 +228,7 @@ void Vic::WriteYUVFrame(const AVFrame* frame, const VicConfig& config) {
         break;
     }
     default:
-        UNREACHABLE();
+        ASSERT(false);
         break;
     }
     gpu.MemoryManager().WriteBlock(output_surface_chroma_address, chroma_buffer.data(),