[CSTrail] NFC: Add dump() methods to SolverTrail

Author: xedin

include/swift/Sema/CSTrail.h

@@ -260,6 +260,10 @@ class SolverTrail {
 
   void undo(unsigned toIndex);
 
+  SWIFT_DEBUG_DUMP;
+  void dump(raw_ostream &OS, unsigned fromIndex = 0,
+            unsigned indent = 0) const LLVM_ATTRIBUTE_USED;
+
 private:
   ConstraintSystem &CS;
 

lib/Sema/CSTrail.cpp

@@ -880,3 +880,11 @@ void SolverTrail::dumpActiveScopeChanges(llvm::raw_ostream &out,
   out.indent(indent);
   out << ")\n";
 }
+
+void SolverTrail::dump() const { dump(llvm::errs()); }
+
+void SolverTrail::dump(raw_ostream &OS, unsigned fromIndex,
+                       unsigned indent) const {
+  for (unsigned i = fromIndex; i < Changes.size(); ++i)
+    Changes[i].dump(OS, CS, indent);
+}