[CSFix] Add a specific kind for IgnoreContextualType

Author: xedin

include/swift/Sema/CSFix.h

@@ -351,6 +351,9 @@ enum class FixKind : uint8_t {
   /// Allow invalid pointer conversions for autoclosure result types as if the
   /// pointer type is a function parameter rather than an autoclosure result.
   AllowAutoClosurePointerConversion,
+
+  /// Ignore externally imposed type.
+  IgnoreContextualType,
 };
 
 class ConstraintFix {
@@ -1938,7 +1941,8 @@ class AllowTupleSplatForSingleParameter final : public ConstraintFix {
 class IgnoreContextualType : public ContextualMismatch {
   IgnoreContextualType(ConstraintSystem &cs, Type resultTy, Type specifiedTy,
                        ConstraintLocator *locator)
-      : ContextualMismatch(cs, resultTy, specifiedTy, locator) {}
+      : ContextualMismatch(cs, FixKind::IgnoreContextualType, resultTy,
+                           specifiedTy, locator) {}
 
 public:
   std::string getName() const override {
@@ -1950,6 +1954,10 @@ class IgnoreContextualType : public ContextualMismatch {
   static IgnoreContextualType *create(ConstraintSystem &cs, Type resultTy,
                                       Type specifiedTy,
                                       ConstraintLocator *locator);
+
+  static bool classof(ConstraintFix *fix) {
+    return fix->getKind() == FixKind::IgnoreContextualType;
+  }
 };
 
 class IgnoreAssignmentDestinationType final : public ContextualMismatch {

lib/Sema/CSSimplify.cpp

@@ -11685,7 +11685,8 @@ ConstraintSystem::SolutionKind ConstraintSystem::simplifyFixConstraint(
     return matchTypes(*elemTy, dictionaryKeyTy, kind, subflags, elemLoc);
   }
 
-  case FixKind::ContextualMismatch: {
+  case FixKind::ContextualMismatch:
+  case FixKind::IgnoreContextualType: {
     auto impact = 1;
 
     auto locator = fix->getLocator();