Merge pull request #15673 from ikesyo/reflection-remote-using-over-typedef

[gardening][Reflection][Remote] Replace `typedef` with `using`

Author: ikesyo

include/swift/Reflection/ReflectionContext.h

@@ -38,9 +38,9 @@
 
 #if defined(__APPLE__) && defined(__MACH__)
 #ifndef __LP64__
-typedef const struct mach_header MachHeader;
+using MachHeader = const struct mach_header;
 #else
-typedef const struct mach_header_64 MachHeader;
+using MachHeader = const struct mach_header_64;
 #endif
 #endif
 

include/swift/Remote/MetadataReader.h

@@ -1491,7 +1491,7 @@ class MetadataReader {
 namespace llvm {
   template<typename Runtime, typename T>
   struct simplify_type<swift::remote::RemoteRef<Runtime, T>> {
-    typedef const T *SimpleType;
+    using SimpleType = const T *;
     static SimpleType
     getSimplifiedValue(swift::remote::RemoteRef<Runtime, T> value) {
       return value.getLocalBuffer();