[ConstraintLocator] NFC: Add isForGenericParameter accessor

Author: xedin

lib/Sema/ConstraintLocator.cpp

@@ -165,6 +165,12 @@ bool ConstraintLocator::isForKeyPathComponent() const {
   });
 }
 
+bool ConstraintLocator::isForGenericParameter() const {
+  auto path = getPath();
+  return !path.empty() &&
+         path.back().getKind() == ConstraintLocator::GenericParameter;
+}
+
 void ConstraintLocator::dump(SourceManager *sm) {
   dump(sm, llvm::errs());
   llvm::errs() << "\n";

lib/Sema/ConstraintLocator.h

@@ -564,6 +564,9 @@ class ConstraintLocator : public llvm::FoldingSetNode {
   /// components.
   bool isForKeyPathComponent() const;
 
+  /// Determine whether this locator points to the generic parameter.
+  bool isForGenericParameter() const;
+
   /// Produce a profile of this locator, for use in a folding set.
   static void Profile(llvm::FoldingSetNodeID &id, Expr *anchor,
                       ArrayRef<PathElement> path);