Fix warnings with pointer arithmetics under 64bit systems

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4147 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/CPLYMeshFileLoader.cpp

@@ -469,7 +469,7 @@ void CPLYMeshFileLoader::fillBuffer()
 	if (EndOfFile)
 		return;
 
-	u32 length = EndPointer - StartPointer;
+	u32 length = (u32)(EndPointer - StartPointer);
 	if (length && StartPointer != Buffer)
 	{
 		// copy the remaining data to the start of the buffer
@@ -647,7 +647,7 @@ c8* CPLYMeshFileLoader::getNextWord()
 		++pos;
 	}
 	--pos;
-	WordLength = pos-StartPointer;
+	WordLength = (s32)(pos-StartPointer);
 	// return pointer to the start of the word
 	return StartPointer;
 }