Store whether or not a shader uses debug printf

* Shaders that use printf will go through the feedback path, even though they
  may not use arrayed descriptors.

renderdoc/driver/shaders/spirv/spirv_reflect.cpp

@@ -1186,6 +1186,10 @@ void Reflector::MakeReflection(const GraphicsAPI sourceAPI, const ShaderStage st
     patchData.outTopo = e.executionModes.outTopo;
   }
 
+  for(auto it = extSets.begin(); it != extSets.end(); it++)
+    if(it->second == "NonSemantic.DebugPrintf")
+      patchData.usesPrintf = true;
+
   // sort system value semantics to the start of the list
   struct sig_param_sort
   {

renderdoc/driver/shaders/spirv/spirv_reflect.h

@@ -65,6 +65,8 @@ struct SPIRVPatchData
 
   // the output topology for tessellation and geometry shaders
   Topology outTopo = Topology::Unknown;
+
+  bool usesPrintf = false;
 };
 
 namespace rdcspv