Fix BlenderDNA for clang cross compiler.

code/BlenderDNA.cpp

@@ -56,10 +56,10 @@ using namespace Assimp::Formatter;
 static bool match4(StreamReaderAny& stream, const char* string) {
     ai_assert( nullptr != string );
     char tmp[] = {
-        (stream).GetI1(),
-        (stream).GetI1(),
-        (stream).GetI1(),
-        (stream).GetI1()
+        (const char)(stream).GetI1(),
+        (const char)(stream).GetI1(),
+        (const char)(stream).GetI1(),
+        (const char)(stream).GetI1()
     };
     return (tmp[0]==string[0] && tmp[1]==string[1] && tmp[2]==string[2] && tmp[3]==string[3]);
 }
@@ -346,10 +346,10 @@ void SectionParser :: Next()
     stream.SetCurrentPos(current.start + current.size);
 
     const char tmp[] = {
-        stream.GetI1(),
-        stream.GetI1(),
-        stream.GetI1(),
-        stream.GetI1()
+        (const char)stream.GetI1(),
+        (const char)stream.GetI1(),
+        (const char)stream.GetI1(),
+        (const char)stream.GetI1()
     };
     current.id = std::string(tmp,tmp[3]?4:tmp[2]?3:tmp[1]?2:1);