shader_ir/decode: Silent implicit sign conversion warning

Co-Authored-By: ReinUsesLisp <reinuseslisp@airmail.cc>

src/video_core/shader/decode/texture.cpp

@@ -564,7 +564,7 @@ std::vector<Node> ShaderIR::GetAoffiCoordinates(Node aoffi_reg, std::size_t coor
             return {{0, 4, 8}, 4, 8, 16};
         }
     }();
-    const u32 mask = (1 << size) - 1;
+    const u32 mask = (1U << size) - 1;
 
     std::vector<Node> aoffi;
     aoffi.reserve(coord_count);
@@ -595,4 +595,4 @@ std::vector<Node> ShaderIR::GetAoffiCoordinates(Node aoffi_reg, std::size_t coor
     return aoffi;
 }
 
-} // namespace VideoCommon::Shader
+} // namespace VideoCommon::Shader