[Reflection] Cache the various DataQuery values.

We can end up querying the pointer size and similar things very frequently, which can be slow. These values don't change for any given reader, so call them once and cache the values locally instead.

rdar://150221008

lib/StaticMirror/ObjectFileContext.cpp

@@ -565,16 +565,18 @@ std::unique_ptr<ReflectionContextHolder> makeReflectionContextForObjectFiles(
   const std::vector<const ObjectFile *> &objectFiles, bool ObjCInterop) {
   auto Reader = std::make_shared<ObjectMemoryReader>(objectFiles);
 
-  uint8_t pointerSize;
-  Reader->queryDataLayout(DataLayoutQueryType::DLQ_GetPointerSize, nullptr,
-                          &pointerSize);
+  auto pointerSize = Reader->getPointerSize();
+  if (!pointerSize) {
+    fputs("unable to get target pointer size\n", stderr);
+    abort();
+  }
 
-  switch (pointerSize) {
+  switch (pointerSize.value()) {
   case 4:
 #define MAKE_CONTEXT(INTEROP, PTRSIZE)                                         \
   makeReflectionContextForMetadataReader<                                      \
       External<INTEROP<RuntimeTarget<PTRSIZE>>>>(std::move(Reader),            \
-                                                 pointerSize)
+                                                 pointerSize.value())
 #if SWIFT_OBJC_INTEROP
     if (ObjCInterop)
       return MAKE_CONTEXT(WithObjCInterop, 4);