Sema: Remove synthesizeWitnessAccessorsForStorage()

We can lazily synthesize accessor witnesses from SILGen now.

Author: slavapestov

lib/Sema/CodeSynthesis.cpp

@@ -1320,22 +1320,6 @@ synthesizeModifyCoroutineSetterBody(AccessorDecl *setter, ASTContext &ctx) {
                                                 setter->getStorage(), ctx);
 }
 
-/// The specified AbstractStorageDecl was just found to satisfy a
-/// protocol property requirement.  Ensure that it has the full
-/// complement of accessors.
-void TypeChecker::synthesizeWitnessAccessorsForStorage(
-                                             AbstractStorageDecl *requirement,
-                                             AbstractStorageDecl *storage) {
-  // Make sure the protocol requirement itself has the right accessors.
-  // FIXME: This should be a request kicked off by SILGen.
-  DeclsToFinalize.insert(requirement);
-
-  requirement->visitExpectedOpaqueAccessors([&](AccessorKind kind) {
-    // Force synthesis if necessary.
-    (void) storage->getSynthesizedAccessor(kind);
-  });
-}
-
 /// Given a VarDecl with a willSet: and/or didSet: specifier, synthesize the
 /// setter which calls them.
 static std::pair<BraceStmt *, bool>

lib/Sema/TypeCheckProtocol.cpp

@@ -2208,12 +2208,6 @@ void ConformanceChecker::recordWitness(ValueDecl *requirement,
   // Record this witness in the conformance.
   auto witness = match.getWitness(TC.Context);
   Conformance->setWitness(requirement, witness);
-
-  // Synthesize accessors for the protocol witness table to use.
-  if (auto storage = dyn_cast<AbstractStorageDecl>(witness.getDecl()))
-    TC.synthesizeWitnessAccessorsForStorage(
-                                        cast<AbstractStorageDecl>(requirement),
-                                        storage);
 }
 
 void ConformanceChecker::recordOptionalWitness(ValueDecl *requirement) {
@@ -5337,12 +5331,6 @@ void DefaultWitnessChecker::recordWitness(
                                   const RequirementMatch &match) {
   Proto->setDefaultWitness(requirement,
                            match.getWitness(TC.Context));
-
-  // Synthesize accessors for the protocol witness table to use.
-  if (auto storage = dyn_cast<AbstractStorageDecl>(match.Witness))
-    TC.synthesizeWitnessAccessorsForStorage(
-                                        cast<AbstractStorageDecl>(requirement),
-                                        storage);
 }
 
 void TypeChecker::inferDefaultWitnesses(ProtocolDecl *proto) {

lib/Sema/TypeChecker.h

@@ -1172,12 +1172,6 @@ class TypeChecker final : public LazyResolver {
   /// target.
   void synthesizeMemberForLookup(NominalTypeDecl *target, DeclName member);
 
-  /// The specified AbstractStorageDecl \c storage was just found to satisfy
-  /// the protocol property \c requirement.  Ensure that it has the full
-  /// complement of accessors.
-  void synthesizeWitnessAccessorsForStorage(AbstractStorageDecl *requirement,
-                                            AbstractStorageDecl *storage);
-
   /// Pre-check the expression, validating any types that occur in the
   /// expression and folding sequence expressions.
   bool preCheckExpression(Expr *&expr, DeclContext *dc);

test/multifile/Inputs/protocol-conformance-let-other.swift

@@ -1,4 +1,3 @@
 public protocol P {
   let x: Int
-  // expected-error@-1 {{immutable property requirement must be declared as 'var' with a '{ get }' specifier}}
 }