[+0-all-args] Document the swift exposed functions in Reflection.mm as being either methods or free functions.

Some of the free functions have method like names, so it is impossible to know
whether or not the given functions use the method convention or the thin
convention. At least now it is documented.

rdar://34222540

Author: gottesmm

stdlib/public/runtime/Reflection.mm

@@ -172,7 +172,13 @@ explicit String(NSString *s)
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wreturn-type-c-linkage"
 
-
+// struct _MagicMirrorData {
+//   internal var value: Any {
+//     @_silgen_name("swift_MagicMirrorData_value")get
+//   }
+// }
+//
+// Since this is a method, owner is passed in at +0.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 AnyReturn swift_MagicMirrorData_value(HeapObject *owner,
                                       const OpaqueValue *value,
@@ -186,6 +192,14 @@ AnyReturn swift_MagicMirrorData_value(HeapObject *owner,
 
   return AnyReturn(result);
 }
+
+// struct _MagicMirrorData {
+//   internal var valueType: Any.Type {
+//     @_silgen_name("swift_MagicMirrorData_valueType")get
+//   }
+// }
+//
+// Since this is a method, owner is passed in at +0.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 const Metadata *swift_MagicMirrorData_valueType(HeapObject *owner,
                                                 const OpaqueValue *value,
@@ -195,6 +209,14 @@ AnyReturn swift_MagicMirrorData_value(HeapObject *owner,
 }
 
 #if SWIFT_OBJC_INTEROP
+
+// struct _MagicMirrorData {
+//   public var objcValue: Any {
+//     @_silgen_name("swift_MagicMirrorData_objcValue")get
+//   }
+// }
+//
+// Since this is a method, owner is at +0.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 AnyReturn swift_MagicMirrorData_objcValue(HeapObject *owner,
                                           const OpaqueValue *value,
@@ -295,6 +317,13 @@ void swift_MagicMirrorData_summary(const Metadata *T, String *result) {
   }
 }
 
+// struct _MagicMirrorData {
+//   public var objcValueType: Any.Type {
+//     @_silgen_name("swift_MagicMirrorData_objcValueType")get
+//   }
+// }
+//
+// This is a method, so owner is at +0.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 const Metadata *swift_MagicMirrorData_objcValueType(HeapObject *owner,
                                                     const OpaqueValue *value,
@@ -351,6 +380,9 @@ static Mirror reflect(HeapObject *owner,
 
 // -- Tuple destructuring.
 
+// internal func _getTupleCount(_: _MagicMirrorData) -> Int
+//
+// This is a free standing function, not a method.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 intptr_t swift_TupleMirror_count(HeapObject *owner,
                                  const OpaqueValue *value,
@@ -360,6 +392,10 @@ intptr_t swift_TupleMirror_count(HeapObject *owner,
   return Tuple->NumElements;
 }
 
+/// internal func _getTupleChild<T>(_: Int, _: _MagicMirrorData) -> (T, _Mirror)
+///
+/// This is a free standing function, not a method.
+///
 /// \param owner passed at +1, consumed.
 /// \param value passed unowned.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
@@ -489,6 +525,9 @@ static bool loadSpecialReferenceStorage(HeapObject *owner,
 
 // -- Struct destructuring.
 
+// internal func _getStructCount(_: _MagicMirrorData) -> Int
+//
+// This is a free standing function, not a method.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 intptr_t swift_StructMirror_count(HeapObject *owner,
                                   const OpaqueValue *value,
@@ -498,6 +537,9 @@ intptr_t swift_StructMirror_count(HeapObject *owner,
   return Struct->Description->Struct.NumFields;
 }
 
+// internal func _getStructChild<T>(_: Int, _: _MagicMirrorData) -> (T, _Mirror)
+//
+// This is a free standing function, not a method.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 void swift_StructMirror_subscript(String *outString,
                                   Mirror *outMirror,
@@ -524,6 +566,7 @@ void swift_StructMirror_subscript(String *outString,
 
   assert(!fieldType.isIndirect() && "indirect struct fields not implemented");
 
+  // This only consumed owner if we succeed.
   if (loadSpecialReferenceStorage(owner, fieldData, fieldType, outMirror))
     return;
 
@@ -576,6 +619,10 @@ static void getEnumMirrorInfo(const OpaqueValue *value,
     *indirectPtr = indirect;
 }
 
+// internal func _swift_EnumMirror_caseName(
+//     _ data: _MagicMirrorData) -> UnsafePointer<CChar>
+//
+// This is a free standing function.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 const char *swift_EnumMirror_caseName(HeapObject *owner,
                                       const OpaqueValue *value,
@@ -596,6 +643,9 @@ static void getEnumMirrorInfo(const OpaqueValue *value,
   return getFieldName(Description.CaseNames, tag);
 }
 
+// internal func _getEnumCaseName<T>(_ value: T) -> UnsafePointer<CChar>?
+//
+// This is a free standing function, not a method.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 const char *swift_EnumCaseName(OpaqueValue *value, const Metadata *type) {
   // Build a magic mirror. Unconditionally destroy the value at the end.
@@ -622,6 +672,9 @@ static void getEnumMirrorInfo(const OpaqueValue *value,
   return result;
 }
 
+// internal func _getEnumCount(_: _MagicMirrorData) -> Int
+//
+// This is a free standing function, not a method.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 intptr_t swift_EnumMirror_count(HeapObject *owner,
                                 const OpaqueValue *value,
@@ -637,6 +690,9 @@ intptr_t swift_EnumMirror_count(HeapObject *owner,
   return (payloadType != nullptr) ? 1 : 0;
 }
 
+// internal func _getEnumChild<T>(_: Int, _: _MagicMirrorData) -> (T, _Mirror)
+//
+// This is a free standing function, not a method.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 void swift_EnumMirror_subscript(String *outString,
                                 Mirror *outMirror,
@@ -685,6 +741,9 @@ static Mirror getMirrorForSuperclass(const ClassMetadata *sup,
                                      const OpaqueValue *value,
                                      const Metadata *type);
 
+// internal func _getClassCount(_: _MagicMirrorData) -> Int
+//
+// This is a free standing function, not a method.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 intptr_t swift_ClassMirror_count(HeapObject *owner,
                                  const OpaqueValue *value,
@@ -701,6 +760,10 @@ intptr_t swift_ClassMirror_count(HeapObject *owner,
   return count;
 }
 
+/// internal func _getClassChild<T>(_: Int, _: _MagicMirrorData) -> (T, _Mirror)
+///
+/// This is a free standing function, not a method.
+///
 /// \param owner passed at +1, consumed.
 /// \param value passed unowned.
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE