LibGLSL: Fill LinkedShaders with dummy IR code

Author: https://github.com/sunverwerth
Commit: 5bab17596d
Pull-request: https://github.com/SerenityOS/serenity/pull/16225
Reviewed-by: https://github.com/ADKaster ✅
Reviewed-by: https://github.com/gmta ✅
Reviewed-by: https://github.com/supercomputer7

Userland/Libraries/LibGLSL/Linker.cpp

@@ -12,7 +12,21 @@ ErrorOr<NonnullOwnPtr<LinkedShader>> Linker::link(Vector<ObjectFile const*> cons
 {
     // FIXME: implement this function
     m_messages = TRY(String::from_utf8(""sv));
-    return adopt_own(*new LinkedShader());
+
+    GPU::IR::Shader shader;
+
+    auto input_name = TRY(String::from_utf8("input0"sv));
+    auto output_name = TRY(String::from_utf8("output0"sv));
+    TRY(shader.inputs.try_append({ move(input_name), GPU::IR::StorageType::Vector4 }));
+    TRY(shader.outputs.try_append({ move(output_name), GPU::IR::StorageType::Vector4 }));
+    GPU::IR::Instruction instruction {
+        GPU::IR::Opcode::Move,
+        { { GPU::IR::StorageLocation::Input, 0 } },
+        { GPU::IR::StorageLocation::Output, 0 }
+    };
+    TRY(shader.instructions.try_append(instruction));
+
+    return adopt_own(*new LinkedShader(shader));
 }
 
 }