[ConstraintSystem] Remove RValueAdjustment locator element

It was used for unresolved member and `.dynamicType` references
as well as a couple of other places, but now unresolved member
references no longer need that due to new implicit "chain result"
AST node and other places could use more precise locators
e.g. new `.dynamicType` locator or `sequence element` for `for in`
loops.

Author: xedin

include/swift/Sema/ConstraintLocatorPathElts.def

@@ -147,8 +147,8 @@ ABSTRACT_LOCATOR_PATH_ELT(AnyRequirement)
   /// A single requirement placed on the type parameters.
   CUSTOM_LOCATOR_PATH_ELT(TypeParameterRequirement)
 
-/// RValue adjustment.
-SIMPLE_LOCATOR_PATH_ELT(RValueAdjustment)
+/// Access to `.dynamicType` element
+SIMPLE_LOCATOR_PATH_ELT(DynamicType)
 
 /// The element type of a sequence in a for ... in ... loop.
 SIMPLE_LOCATOR_PATH_ELT(SequenceElementType)

lib/Sema/BuilderTransform.cpp

@@ -810,10 +810,10 @@ class BuilderClosureVisitor
     VarDecl *arrayVar = buildVar(loc);
     Type arrayElementType = cs->createTypeVariable(
         cs->getConstraintLocator(forEachStmt), 0);
-    cs->addConstraint(
-        ConstraintKind::Equal, cs->getType(bodyVar), arrayElementType,
-        cs->getConstraintLocator(
-          forEachStmt, ConstraintLocator::RValueAdjustment));
+    cs->addConstraint(ConstraintKind::Equal, cs->getType(bodyVar),
+                      arrayElementType,
+                      cs->getConstraintLocator(
+                          forEachStmt, ConstraintLocator::SequenceElementType));
     Type arrayType = ArraySliceType::get(arrayElementType);
     cs->setType(arrayVar, arrayType);
 

lib/Sema/CSDiagnostics.cpp

@@ -2463,9 +2463,6 @@ void ContextualFailure::tryFixIts(InFlightDiagnostic &diagnostic) const {
 }
 
 bool ContextualFailure::diagnoseMissingFunctionCall() const {
-  if (getLocator()->isLastElement<LocatorPathElt::RValueAdjustment>())
-    return false;
-
   if (getLocator()
       ->isLastElement<LocatorPathElt::UnresolvedMemberChainResult>())
     return false;

lib/Sema/CSGen.cpp

@@ -2591,9 +2591,9 @@ namespace {
     Type visitDynamicTypeExpr(DynamicTypeExpr *expr) {
       auto tv = CS.createTypeVariable(CS.getConstraintLocator(expr),
                                       TVO_CanBindToNoEscape);
-      CS.addConstraint(ConstraintKind::DynamicTypeOf, tv,
-                       CS.getType(expr->getBase()),
-           CS.getConstraintLocator(expr, ConstraintLocator::RValueAdjustment));
+      CS.addConstraint(
+          ConstraintKind::DynamicTypeOf, tv, CS.getType(expr->getBase()),
+          CS.getConstraintLocator(expr, ConstraintLocator::DynamicType));
       return tv;
     }
 

lib/Sema/CSSimplify.cpp

@@ -4371,9 +4371,6 @@ bool ConstraintSystem::repairFailures(
     break;
   }
 
-  case ConstraintLocator::RValueAdjustment:
-    return true;
-
   case ConstraintLocator::UnresolvedMemberChainResult: {
     if (repairViaOptionalUnwrap(*this, lhs, rhs, matchKind, conversionsOrFixes,
                                 locator))

lib/Sema/ConstraintLocator.cpp

@@ -54,7 +54,7 @@ unsigned LocatorPathElt::getNewSummaryFlags() const {
   case ConstraintLocator::ParentType:
   case ConstraintLocator::ExistentialSuperclassType:
   case ConstraintLocator::LValueConversion:
-  case ConstraintLocator::RValueAdjustment:
+  case ConstraintLocator::DynamicType:
   case ConstraintLocator::SubscriptMember:
   case ConstraintLocator::OpenedGeneric:
   case ConstraintLocator::GenericParameter:
@@ -350,8 +350,8 @@ void ConstraintLocator::dump(SourceManager *sm, raw_ostream &out) const {
       out << "@lvalue-to-inout conversion";
       break;
 
-    case RValueAdjustment:
-      out << "rvalue adjustment";
+    case DynamicType:
+      out << "`.dynamicType` reference";
       break;
 
     case SubscriptMember:

lib/Sema/ConstraintSystem.cpp

@@ -1868,8 +1868,9 @@ static std::pair<Type, Type> getTypeOfReferenceWithSpecialTypeCheckingSemantics(
     FunctionType::Param inputArg(input,
                                  CS.getASTContext().getIdentifier("of"));
 
-    CS.addConstraint(ConstraintKind::DynamicTypeOf, output, input,
-        CS.getConstraintLocator(locator, ConstraintLocator::RValueAdjustment));
+    CS.addConstraint(
+        ConstraintKind::DynamicTypeOf, output, input,
+        CS.getConstraintLocator(locator, ConstraintLocator::DynamicType));
     auto refType = FunctionType::get({inputArg}, output);
     return {refType, refType};
   }
@@ -1883,9 +1884,8 @@ static std::pair<Type, Type> getTypeOfReferenceWithSpecialTypeCheckingSemantics(
     auto escapeClosure = CS.createTypeVariable(
         CS.getConstraintLocator(locator, ConstraintLocator::FunctionArgument),
         TVO_CanBindToNoEscape);
-    CS.addConstraint(ConstraintKind::EscapableFunctionOf,
-         escapeClosure, noescapeClosure,
-         CS.getConstraintLocator(locator, ConstraintLocator::RValueAdjustment));
+    CS.addConstraint(ConstraintKind::EscapableFunctionOf, escapeClosure,
+                     noescapeClosure, CS.getConstraintLocator(locator));
     auto result = CS.createTypeVariable(
         CS.getConstraintLocator(locator, ConstraintLocator::FunctionResult),
         TVO_CanBindToNoEscape);
@@ -1916,9 +1916,8 @@ static std::pair<Type, Type> getTypeOfReferenceWithSpecialTypeCheckingSemantics(
     auto existentialTy = CS.createTypeVariable(
         CS.getConstraintLocator(locator, ConstraintLocator::FunctionArgument),
         TVO_CanBindToNoEscape);
-    CS.addConstraint(ConstraintKind::OpenedExistentialOf,
-         openedTy, existentialTy,
-         CS.getConstraintLocator(locator, ConstraintLocator::RValueAdjustment));
+    CS.addConstraint(ConstraintKind::OpenedExistentialOf, openedTy,
+                     existentialTy, CS.getConstraintLocator(locator));
     auto result = CS.createTypeVariable(
         CS.getConstraintLocator(locator, ConstraintLocator::FunctionResult),
         TVO_CanBindToNoEscape);
@@ -3914,7 +3913,7 @@ void constraints::simplifyLocator(ASTNode &anchor,
 
     case ConstraintLocator::AutoclosureResult:
     case ConstraintLocator::LValueConversion:
-    case ConstraintLocator::RValueAdjustment:
+    case ConstraintLocator::DynamicType:
     case ConstraintLocator::UnresolvedMember:
     case ConstraintLocator::ImplicitCallAsFunction:
       // Arguments in autoclosure positions, lvalue and rvalue adjustments,