message: Bake in Vulkan_Debug_StepToDebugValue
  * The behaviour with this set to true is significantly better for lightly-
  optimised code as comes out of HLSL legalisation, with little penalty for
  other code.
diff: #include "spirv_op_helpers.h"
  #include "var_dispatch_helpers.h"
  -RDOC_CONFIG(bool, Vulkan_Debug_StepToDebugValue, false,
  - "Treat DebugValue as a steppable executable instruction.");
  -
  static bool ContainsNaNInf(const ShaderVariable &var)
  {
  bool ret = false;
  @@ -587,8 +584,6 @@ void ThreadState::SkipIgnoredInstructions()
  if(op == Op::ExtInst)
  {
  if(debugger.IsDebugExtInstSet(Id::fromWord(it.word(3))))
  - {
  - if(Vulkan_Debug_StepToDebugValue())
  {
  if(ShaderDbg(it.word(4)) != ShaderDbg::Value || !debugger.InDebugScope(nextInstruction))
  {
  @@ -596,12 +591,6 @@ void ThreadState::SkipIgnoredInstructions()
  continue;
  }
  }
  - else
  - {
  - nextInstruction++;
  - continue;
  - }
  - }
  }
  if(op == Op::SelectionMerge)
  