DXIL Debugger preparation changes

Add DXILDebug::[Debugger,ThreadState] as friends to DXIL::Program
Expose DXIL::isUndef(const DXIL::Value* v); for use in the DXIL Debugger
Add more stubs to DXILDebug::[DebugAPIWrapper, ThreadState, GlobalState]

renderdoc/driver/shaders/dxil/dxil_bytecode.h

@@ -41,6 +41,12 @@ namespace LLVMBC
 struct BlockOrRecord;
 };
 
+namespace DXILDebug
+{
+class Debugger;
+struct ThreadState;
+};
+
 namespace DXIL
 {
 struct BumpAllocator
@@ -1498,6 +1504,8 @@ struct ResourceReference
 
 class Program : public DXBC::IDebugInfo
 {
+  friend DXILDebug::Debugger;
+  friend DXILDebug::ThreadState;
 public:
   Program(const byte *bytes, size_t length);
   Program(const Program &o) = delete;
@@ -1667,6 +1675,8 @@ bool getival(const Value *v, T &out)
   return false;
 }
 
+bool isUndef(const Value *v);
+
 };    // namespace DXIL
 
 DECLARE_REFLECTION_ENUM(DXIL::Attribute);

renderdoc/driver/shaders/dxil/dxil_debug.h

@@ -30,6 +30,9 @@
 
 namespace DXILDebug
 {
+typedef rdcstr Id;
+class Debugger;
+struct GlobalState;
 struct BindingSlot
 {
   BindingSlot() : shaderRegister(UINT32_MAX), registerSpace(UINT32_MAX) {}
@@ -53,8 +56,22 @@ struct BindingSlot
   uint32_t registerSpace;
 };
 
-struct Debugger : public DXBCContainerDebugger
+class DebugAPIWrapper
 {
+};
+
+struct ThreadState
+{
+};
+
+struct GlobalState
+{
+  GlobalState() = default;
+};
+
+class Debugger : public DXBCContainerDebugger
+{
+public:
   Debugger() : DXBCContainerDebugger(true){};
 };