ASTScope: unqualifiedLookup() entry point does not need the name

If we're searching for a declaration with a given name, the name
should be entirely encapsulated inside the DeclConsumer.

Otherwise, there might not be a specific name at all, if we're
performing code completion for example (once LookupVisibleDecls
starts to use ASTScope, anyway).

Author: slavapestov

include/swift/AST/ASTScope.h

@@ -354,7 +354,7 @@ class ASTScopeImpl {
 
   /// Entry point into ASTScopeImpl-land for lookups
   static void
-  unqualifiedLookup(SourceFile *, DeclNameRef, SourceLoc, DeclConsumer);
+  unqualifiedLookup(SourceFile *, SourceLoc, DeclConsumer);
 
   /// Entry point into ASTScopeImpl-land for labeled statement lookups.
   static llvm::SmallVector<LabeledStmt *, 4>
@@ -366,7 +366,6 @@ class ASTScopeImpl {
 #pragma mark - - lookup- starting point
 private:
   static const ASTScopeImpl *findStartingScopeForLookup(SourceFile *,
-                                                        const DeclNameRef name,
                                                         const SourceLoc where);
 
 protected:

include/swift/AST/NameLookup.h

@@ -681,7 +681,7 @@ class ASTScope {
   /// Flesh out the tree for dumping
   void buildFullyExpandedTree();
 
-  static void unqualifiedLookup(SourceFile *, DeclNameRef, SourceLoc,
+  static void unqualifiedLookup(SourceFile *, SourceLoc,
                                 namelookup::AbstractASTScopeDeclConsumer &);
 
   /// Entry point to record the visible statement labels from the given

lib/AST/ASTScope.cpp

@@ -39,11 +39,11 @@ using namespace ast_scope;
 #pragma mark ASTScope
 
 void ASTScope::unqualifiedLookup(
-    SourceFile *SF, DeclNameRef name, SourceLoc loc,
+    SourceFile *SF, SourceLoc loc,
     namelookup::AbstractASTScopeDeclConsumer &consumer) {
   if (auto *s = SF->getASTContext().Stats)
     ++s->getFrontendCounters().NumASTScopeLookups;
-  ASTScopeImpl::unqualifiedLookup(SF, name, loc, consumer);
+  ASTScopeImpl::unqualifiedLookup(SF, loc, consumer);
 }
 
 llvm::SmallVector<LabeledStmt *, 4> ASTScope::lookupLabeledStmts(

lib/AST/ASTScopeLookup.cpp

@@ -36,21 +36,16 @@ using namespace namelookup;
 using namespace ast_scope;
 
 void ASTScopeImpl::unqualifiedLookup(
-    SourceFile *sourceFile, const DeclNameRef name, const SourceLoc loc,
-    DeclConsumer consumer) {
+    SourceFile *sourceFile, const SourceLoc loc, DeclConsumer consumer) {
   const auto *start =
-      findStartingScopeForLookup(sourceFile, name, loc);
+      findStartingScopeForLookup(sourceFile, loc);
   if (start)
     start->lookup(nullptr, nullptr, consumer);
 }
 
 const ASTScopeImpl *ASTScopeImpl::findStartingScopeForLookup(
-    SourceFile *sourceFile, const DeclNameRef name, const SourceLoc loc) {
+    SourceFile *sourceFile, const SourceLoc loc) {
   auto *const fileScope = sourceFile->getScope().impl;
-  // Parser may have added decls to source file, since previous lookup
-  if (name.isOperator())
-    return fileScope; // operators always at file scope
-
   const auto *innermost = fileScope->findInnermostEnclosingScope(loc, nullptr);
   ASTScopeAssert(innermost->getWasExpanded(),
                  "If looking in a scope, it must have been expanded.");

lib/AST/UnqualifiedLookup.cpp

@@ -303,7 +303,9 @@ void UnqualifiedLookupFactory::performUnqualifiedLookup() {
                                   DC->getParentSourceFile());
 
   if (Loc.isValid()) {
-    lookInASTScopes();
+    // Operator lookup is always global, for the time being.
+    if (!Name.isOperator())
+      lookInASTScopes();
   } else {
     assert(DC->isModuleScopeContext() &&
            "Unqualified lookup without a source location must start from "
@@ -543,8 +545,7 @@ void UnqualifiedLookupFactory::lookInASTScopes() {
   stopForDebuggingIfStartingTargetLookup(true);
 #endif
 
-  ASTScope::unqualifiedLookup(DC->getParentSourceFile(),
-                              Name, Loc, consumer);
+  ASTScope::unqualifiedLookup(DC->getParentSourceFile(), Loc, consumer);
 }
 
 void ASTScopeDeclConsumerForUnqualifiedLookup::maybeUpdateSelfDC(