[CSFix] NFC: Remove obsolete IgnoreKeyPathContextualMismatch fix

Author: xedin

include/swift/Sema/CSFix.h

@@ -393,10 +393,6 @@ enum class FixKind : uint8_t {
   /// is marked as `inout`.
   AllowConversionThroughInOut,
 
-  /// Ignore either capability (read/write) or type mismatch in conversion
-  /// between two key path types.
-  IgnoreKeyPathContextualMismatch,
-
   /// Ignore a type mismatch between deduced element type and externally
   /// imposed one.
   IgnoreCollectionElementContextualMismatch,
@@ -1167,36 +1163,6 @@ class GenericArgumentsMismatch final
   }
 };
 
-/// Detect situations where key path doesn't have capability required
-/// by the context e.g. read-only vs. writable, or either root or value
-/// types are incorrect e.g.
-///
-/// ```swift
-/// struct S { let foo: Int }
-/// let _: WritableKeyPath<S, Int> = \.foo
-/// ```
-///
-/// Here context requires a writable key path but `foo` property is
-/// read-only.
-class KeyPathContextualMismatch final : public ContextualMismatch {
-  KeyPathContextualMismatch(ConstraintSystem &cs, Type lhs, Type rhs,
-                            ConstraintLocator *locator)
-      : ContextualMismatch(cs, FixKind::IgnoreKeyPathContextualMismatch, lhs,
-                           rhs, locator) {}
-
-public:
-  std::string getName() const override {
-    return "fix key path contextual mismatch";
-  }
-
-  static KeyPathContextualMismatch *
-  create(ConstraintSystem &cs, Type lhs, Type rhs, ConstraintLocator *locator);
-
-  static bool classof(const ConstraintFix *fix) {
-    return fix->getKind() == FixKind::IgnoreKeyPathContextualMismatch;
-  }
-};
-
 /// Detect situations when argument of the @autoclosure parameter is itself
 /// marked as @autoclosure and is not applied. Form a fix which suggests a
 /// proper way to forward such arguments, e.g.:

lib/Sema/CSFix.cpp

@@ -1296,13 +1296,6 @@ AllowInvalidRefInKeyPath::create(ConstraintSystem &cs, RefKind kind,
       AllowInvalidRefInKeyPath(cs, kind, member, locator);
 }
 
-KeyPathContextualMismatch *
-KeyPathContextualMismatch::create(ConstraintSystem &cs, Type lhs, Type rhs,
-                                  ConstraintLocator *locator) {
-  return new (cs.getAllocator())
-      KeyPathContextualMismatch(cs, lhs, rhs, locator);
-}
-
 bool RemoveAddressOf::diagnose(const Solution &solution, bool asNote) const {
   InvalidUseOfAddressOf failure(solution, getFromType(), getToType(),
                                 getLocator());

lib/Sema/CSSimplify.cpp

@@ -15055,7 +15055,6 @@ ConstraintSystem::SolutionKind ConstraintSystem::simplifyFixConstraint(
   case FixKind::RemoveExtraneousArguments:
   case FixKind::SpecifyTypeForPlaceholder:
   case FixKind::AllowAutoClosurePointerConversion:
-  case FixKind::IgnoreKeyPathContextualMismatch:
   case FixKind::NotCompileTimeConst:
   case FixKind::RenameConflictingPatternVariables:
   case FixKind::MustBeCopyable: