Cherry-pick changes from more recent RapidJSON to reduce warnings (#646)

* fix C5054 (cherry-pick change from Tencent/rapidjson#1817)

* fix C4099  in Rapidjson. Cherry-picks the following:
Tencent/rapidjson@d87b698
Tencent/rapidjson#1568

primedev/thirdparty/rapidjson/document.h

@@ -198,17 +198,19 @@ class GenericMemberIterator
 // class-based member iterator implementation disabled, use plain pointers
 
 template <bool Const, typename Encoding, typename Allocator>
-struct GenericMemberIterator;
+class GenericMemberIterator;
 
 //! non-const GenericMemberIterator
 template <typename Encoding, typename Allocator>
-struct GenericMemberIterator<false,Encoding,Allocator> {
+class GenericMemberIterator<false,Encoding,Allocator> {
+public:
     //! use plain pointer as iterator type
     typedef GenericMember<Encoding,Allocator>* Iterator;
 };
 //! const GenericMemberIterator
 template <typename Encoding, typename Allocator>
-struct GenericMemberIterator<true,Encoding,Allocator> {
+class GenericMemberIterator<true,Encoding,Allocator> {
+public:
     //! use plain const pointer as iterator type
     typedef const GenericMember<Encoding,Allocator>* Iterator;
 };
@@ -1822,17 +1824,18 @@ class GenericValue {
 
         // Initial flags of different types.
         kNullFlag = kNullType,
-        kTrueFlag = kTrueType | kBoolFlag,
-        kFalseFlag = kFalseType | kBoolFlag,
-        kNumberIntFlag = kNumberType | kNumberFlag | kIntFlag | kInt64Flag,
-        kNumberUintFlag = kNumberType | kNumberFlag | kUintFlag | kUint64Flag | kInt64Flag,
-        kNumberInt64Flag = kNumberType | kNumberFlag | kInt64Flag,
-        kNumberUint64Flag = kNumberType | kNumberFlag | kUint64Flag,
-        kNumberDoubleFlag = kNumberType | kNumberFlag | kDoubleFlag,
-        kNumberAnyFlag = kNumberType | kNumberFlag | kIntFlag | kInt64Flag | kUintFlag | kUint64Flag | kDoubleFlag,
-        kConstStringFlag = kStringType | kStringFlag,
-        kCopyStringFlag = kStringType | kStringFlag | kCopyFlag,
-        kShortStringFlag = kStringType | kStringFlag | kCopyFlag | kInlineStrFlag,
+        // These casts are added to suppress the warning on MSVC about bitwise operations between enums of different types.
+        kTrueFlag = static_cast<int>(kTrueType) | static_cast<int>(kBoolFlag),
+        kFalseFlag = static_cast<int>(kFalseType) | static_cast<int>(kBoolFlag),
+        kNumberIntFlag = static_cast<int>(kNumberType) | static_cast<int>(kNumberFlag | kIntFlag | kInt64Flag),
+        kNumberUintFlag = static_cast<int>(kNumberType) | static_cast<int>(kNumberFlag | kUintFlag | kUint64Flag | kInt64Flag),
+        kNumberInt64Flag = static_cast<int>(kNumberType) | static_cast<int>(kNumberFlag | kInt64Flag),
+        kNumberUint64Flag = static_cast<int>(kNumberType) | static_cast<int>(kNumberFlag | kUint64Flag),
+        kNumberDoubleFlag = static_cast<int>(kNumberType) | static_cast<int>(kNumberFlag | kDoubleFlag),
+        kNumberAnyFlag = static_cast<int>(kNumberType) | static_cast<int>(kNumberFlag | kIntFlag | kInt64Flag | kUintFlag | kUint64Flag | kDoubleFlag),
+        kConstStringFlag = static_cast<int>(kStringType) | static_cast<int>(kStringFlag),
+        kCopyStringFlag = static_cast<int>(kStringType) | static_cast<int>(kStringFlag | kCopyFlag),
+        kShortStringFlag = static_cast<int>(kStringType) | static_cast<int>(kStringFlag | kCopyFlag | kInlineStrFlag),
         kObjectFlag = kObjectType,
         kArrayFlag = kArrayType,