glasm: Implement IsHelperInvocation

src/shader_recompiler/backend/glasm/emit_glasm_instructions.h

@@ -70,7 +70,7 @@ void EmitWorkgroupId(EmitContext& ctx, IR::Inst& inst);
 void EmitLocalInvocationId(EmitContext& ctx, IR::Inst& inst);
 void EmitInvocationId(EmitContext& ctx, IR::Inst& inst);
 void EmitSampleId(EmitContext& ctx);
-void EmitIsHelperInvocation(EmitContext& ctx);
+void EmitIsHelperInvocation(EmitContext& ctx, IR::Inst& inst);
 void EmitYDirection(EmitContext& ctx);
 void EmitLoadLocal(EmitContext& ctx, IR::Inst& inst, ScalarU32 word_offset);
 void EmitWriteLocal(EmitContext& ctx, ScalarU32 word_offset, ScalarU32 value);

src/shader_recompiler/backend/glasm/emit_glasm_not_implemented.cpp

@@ -168,8 +168,8 @@ void EmitSampleId(EmitContext& ctx) {
     NotImplemented();
 }
 
-void EmitIsHelperInvocation(EmitContext& ctx) {
-    NotImplemented();
+void EmitIsHelperInvocation(EmitContext& ctx, IR::Inst& inst) {
+    ctx.Add("MOV.S {}.x,fragment.helperthread.x;", inst);
 }
 
 void EmitYDirection(EmitContext& ctx) {