Comment about thread safety requirements in Spirv debugger ids container

renderdoc/driver/shaders/spirv/spirv_common.h

@@ -209,6 +209,7 @@ private:
   T dummy;
 };
 
+// This must be a thread safe container
 template <typename T>
 class DenseIdMap : public rdcarray<T>
 {

renderdoc/driver/shaders/spirv/spirv_debug.cpp

@@ -329,6 +329,7 @@ void ThreadState::EnterFunction(const rdcarray<Id> &arguments)
   SkipIgnoredInstructions();
 }
 
+// This must be thread safe : it is called from multiple threads
 const ShaderVariable &ThreadState::GetSrc(Id id) const
 {
   return ids[id];

renderdoc/driver/shaders/spirv/spirv_debug.h

@@ -286,6 +286,7 @@ struct ThreadState
   // thread-local private variables
   rdcarray<ShaderVariable> privates;
 
+  // This must be a thread safe container
   // every ID's variable, if a pointer it may be pointing at a ShaderVariable stored elsewhere
   DenseIdMap<ShaderVariable> ids;