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.

renderdoc/driver/shaders/spirv/spirv_debug.cpp

@@ -32,9 +32,6 @@
 #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;
@@ -588,15 +585,7 @@ void ThreadState::SkipIgnoredInstructions()
     {
       if(debugger.IsDebugExtInstSet(Id::fromWord(it.word(3))))
       {
-        if(Vulkan_Debug_StepToDebugValue())
-        {
-          if(ShaderDbg(it.word(4)) != ShaderDbg::Value || !debugger.InDebugScope(nextInstruction))
-          {
-            nextInstruction++;
-            continue;
-          }
-        }
-        else
+        if(ShaderDbg(it.word(4)) != ShaderDbg::Value || !debugger.InDebugScope(nextInstruction))
         {
           nextInstruction++;
           continue;