HLSL: Remove workarounds for assigning to opaques.

This assumes it will be combined with optimizing transforms
that eliminate assignments to opaques.

glslang/MachineIndependent/localintermediate.h

@@ -234,7 +234,8 @@ public:
         hlslOffsets(false),
         useStorageBuffer(false),
         hlslIoMapping(false),
-        textureSamplerTransformMode(EShTexSampTransKeep)
+        textureSamplerTransformMode(EShTexSampTransKeep),
+        needToLegalize(false)
     {
         localSize[0] = 1;
         localSize[1] = 1;
@@ -610,6 +611,9 @@ public:
     void addProcessArgument(const std::string& arg) { processes.addArgument(arg); }
     const std::vector<std::string>& getProcesses() const { return processes.getProcesses(); }
 
+    void setNeedsLegalization() { needToLegalize = true; }
+    bool needsLegalization() const { return needToLegalize; }
+
     const char* const implicitThisName;
 
 protected:
@@ -708,6 +712,8 @@ protected:
     // for OpModuleProcessed, or equivalent
     TProcesses processes;
 
+    bool needToLegalize;
+
 private:
     void operator=(TIntermediate&); // prevent assignments
 };