glsl_decompiler: Fixup geometry shaders

src/video_core/renderer_opengl/gl_shader_gen.cpp

@@ -84,11 +84,7 @@ ProgramResult GenerateGeometryShader(const ShaderSetup& setup) {
     out += "#extension GL_ARB_separate_shader_objects : enable\n";
     out += GetCommonDeclarations();
 
-    out += R"(out gl_PerVertex {
-    vec4 gl_Position;
-};
-
-layout (location = 0) in vec4 gs_position[];
+    out += R"(layout (location = 0) in vec4 gs_position[];
 layout (location = 0) out vec4 position;
 
 layout (std140) uniform gs_config {

src/video_core/shader/glsl_decompiler.cpp

@@ -207,6 +207,22 @@ private:
         if (stage != ShaderStage::Vertex)
             return;
 
+        DeclareVertexRedeclarations();
+    }
+
+    void DeclareGeometry() {
+        if (stage != ShaderStage::Geometry)
+            return;
+
+        const auto topology = GetTopologyName(header.common3.output_topology);
+        const auto max_vertices = std::to_string(header.common4.max_output_vertices);
+        code.AddLine("layout (" + topology + ", max_vertices = " + max_vertices + ") out;");
+        code.AddNewLine();
+
+        DeclareVertexRedeclarations();
+    }
+
+    void DeclareVertexRedeclarations() {
         bool clip_distances_declared = false;
 
         code.AddLine("out gl_PerVertex {");
@@ -229,16 +245,6 @@ private:
         code.AddNewLine();
     }
 
-    void DeclareGeometry() {
-        if (stage != ShaderStage::Geometry)
-            return;
-
-        const auto topology = GetTopologyName(header.common3.output_topology);
-        const auto max_vertices = std::to_string(header.common4.max_output_vertices);
-        code.AddLine("layout (" + topology + ", max_vertices = " + max_vertices + ") out;");
-        code.AddNewLine();
-    }
-
     void DeclareRegisters() {
         const auto& registers = ir.GetRegisters();
         for (const u32 gpr : registers) {