shader_ir/other: Implement S2R InvocationId

src/video_core/renderer_opengl/gl_shader_decompiler.cpp

@@ -1915,6 +1915,10 @@ private:
         return {};
     }
 
+    Expression InvocationId(Operation operation) {
+        return {"gl_InvocationID", Type::Int};
+    }
+
     Expression YNegate(Operation operation) {
         return {"y_direction", Type::Float};
     }
@@ -2153,6 +2157,7 @@ private:
         &GLSLDecompiler::EmitVertex,
         &GLSLDecompiler::EndPrimitive,
 
+        &GLSLDecompiler::InvocationId,
         &GLSLDecompiler::YNegate,
         &GLSLDecompiler::LocalInvocationId<0>,
         &GLSLDecompiler::LocalInvocationId<1>,

src/video_core/renderer_vulkan/vk_shader_decompiler.cpp

@@ -2357,6 +2357,7 @@ private:
         &SPIRVDecompiler::EmitVertex,
         &SPIRVDecompiler::EndPrimitive,
 
+        &SPIRVDecompiler::InvocationId,
         &SPIRVDecompiler::YNegate,
         &SPIRVDecompiler::LocalInvocationId<0>,
         &SPIRVDecompiler::LocalInvocationId<1>,

src/video_core/shader/decode/other.cpp

@@ -69,6 +69,8 @@ u32 ShaderIR::DecodeOther(NodeBlock& bb, u32 pc) {
     case OpCode::Id::MOV_SYS: {
         const Node value = [this, instr] {
             switch (instr.sys20) {
+            case SystemVariable::InvocationId:
+                return Operation(OperationCode::InvocationId);
             case SystemVariable::Ydirection:
                 return Operation(OperationCode::YNegate);
             case SystemVariable::InvocationInfo:

src/video_core/shader/node.h

@@ -172,6 +172,7 @@ enum class OperationCode {
     EmitVertex,   /// () -> void
     EndPrimitive, /// () -> void
 
+    InvocationId,       /// () -> int
     YNegate,            /// () -> float
     LocalInvocationIdX, /// () -> uint
     LocalInvocationIdY, /// () -> uint