Add wxInt64 support to wxText{Input,Output}Stream.

Add explicit Read64[S]() and Write64() methods.

Closes #14685.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76171 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/txtstrm.h

@@ -113,6 +113,24 @@ public:
     */
     wxInt32 Read32S(int base = 10);
 
+    /**
+        Reads a 64 bit unsigned integer from the stream.
+
+        See Read8() for the description of the @a base parameter.
+
+        @since 3.1.0
+    */
+    wxUint64 Read64(int base = 10);
+
+    /**
+        Reads a 64 bit signed integer from the stream.
+
+        See Read8() for the description of the @a base parameter.
+
+        @since 3.1.0
+    */
+    wxInt64 Read64S(int base = 10);
+
     /**
         Reads a single unsigned byte from the stream, given in base @a base.
 
@@ -283,15 +301,22 @@ public:
     void SetMode(wxEOL mode = wxEOL_NATIVE);
 
     /**
-        Writes the 16 bit integer @a i16 to the stream.
+        Writes the 64 bit integer @a i64 to the stream.
+
+        @since 3.1.0
     */
-    void Write16(wxUint16 i16);
+    void Write64(wxUint64 i64);
 
     /**
         Writes the 32 bit integer @a i32 to the stream.
     */
     void Write32(wxUint32 i32);
 
+    /**
+        Writes the 16 bit integer @a i16 to the stream.
+    */
+    void Write16(wxUint16 i16);
+
     /**
         Writes the single byte @a i8 to the stream.
     */