AST: Fix a typo in missingImportsForDefiningModule().

Author: tshortli

lib/Sema/TypeCheckNameLookup.cpp

@@ -835,7 +835,7 @@ missingImportsForDefiningModule(ModuleDecl *owningModule, SourceFile &sf) {
   }
 
   std::sort(result.begin(), result.end(), [](ModuleDecl *LHS, ModuleDecl *RHS) {
-    return LHS->getNameStr() < LHS->getNameStr();
+    return LHS->getNameStr() < RHS->getNameStr();
   });
 
   return result;

test/CrossImport/member-import-visibility.swift

@@ -39,8 +39,8 @@ import Swift
 // expected-note@-1 2 {{add import of module 'DeclaringLibrary'}}
 
 private func test() {
-  returnsDeclaringTy().overlayMember() // expected-error {{instance method 'overlayMember()' is not available due to missing imports of defining modules 'DeclaringLibrary' and 'BystandingLibrary'}}
-  returnsBystandingTy().overlayMember() // expected-error {{instance method 'overlayMember()' is not available due to missing imports of defining modules 'DeclaringLibrary' and 'BystandingLibrary'}}
+  returnsDeclaringTy().overlayMember() // expected-error {{instance method 'overlayMember()' is not available due to missing imports of defining modules 'BystandingLibrary' and 'DeclaringLibrary'}}
+  returnsBystandingTy().overlayMember() // expected-error {{instance method 'overlayMember()' is not available due to missing imports of defining modules 'BystandingLibrary' and 'DeclaringLibrary'}}
 }
 
 //--- BothDeclaringAndBystanding.swift