[CSStep] Use # of disjunctions directly to determine component ordering

Author: xedin

lib/Sema/CSStep.cpp

@@ -188,7 +188,7 @@ void SplitterStep::computeFollowupSteps(
   // want to have smaller/faster components at the back of the list.
   std::sort(componentSteps.begin(), componentSteps.end(),
             [](const ComponentStep *lhs, const ComponentStep *rhs) {
-              return lhs > rhs;
+              return lhs->disjunctionCount() > rhs->disjunctionCount();
             });
 }
 

lib/Sema/CSStep.h

@@ -361,9 +361,8 @@ class ComponentStep final : public SolverStep {
   StepResult take(bool prevFailed) override;
   StepResult resume(bool prevFailed) override;
 
-  bool operator>(const ComponentStep *other) const {
-    return NumDisjunctions > other->NumDisjunctions;
-  }
+  // The number of disjunction constraints associated with this component.
+  unsigned disjunctionCount() const { return NumDisjunctions; }
 
   void print(llvm::raw_ostream &Out) override {
     Out << "ComponentStep with at #" << Index << '\n';