[cxx-interop] always mark begin and end methods as unsafe (to help automatic rac conformance); update tests accordingly.

Author: zoecarver

lib/ClangImporter/ClangImporter.cpp

@@ -6791,6 +6791,12 @@ bool IsSafeUseOfCxxDecl::evaluate(Evaluator &evaluator,
     if (isForeignReferenceType(method->getReturnType()))
       return true;
 
+    // begin and end methods likely return an interator, so they're unsafe. This
+    // is required so that automatic the conformance to RAC works properly.
+    if (method->getNameAsString() == "begin" ||
+        method->getNameAsString() == "end")
+      return false;
+
     auto parentQualType = method
       ->getParent()->getTypeForDecl()->getCanonicalTypeUnqualified();
 

test/Interop/Cxx/stdlib/overlay/Inputs/custom-sequence.h

@@ -24,9 +24,7 @@ struct SimpleCopyAwareSequence {
   SimpleCopyAwareSequence(const SimpleCopyAwareSequence &other) { copiesCount++; }
 };
 
-struct
-  __attribute__((swift_attr("import_owned")))
-SimpleArrayWrapper {
+struct SimpleArrayWrapper {
 private:
   int a[5] = {10, 20, 30, 40, 50};
 
@@ -35,9 +33,7 @@ SimpleArrayWrapper {
   const int *end() const __attribute__((returns_nonnull)) { return &a[5]; }
 };
 
-struct
-  __attribute__((swift_attr("import_owned")))
-SimpleArrayWrapperNullableIterators {
+struct SimpleArrayWrapperNullableIterators {
 private:
   int a[5] = {10, 20, 30, 40, 50};
 
@@ -46,9 +42,7 @@ SimpleArrayWrapperNullableIterators {
   const int *end() const { return &a[5]; }
 };
 
-struct
-  __attribute__((swift_attr("import_owned")))
-SimpleEmptySequence {
+struct SimpleEmptySequence {
   const int *begin() const { return nullptr; }
   const int *end() const { return nullptr; }
 };