Supress unsigned-integer-overflow for PaddingBytes (#5647)

include/flatbuffers/base.h

@@ -382,6 +382,7 @@ template<typename T> __supress_ubsan__("alignment") void WriteScalar(void *p, Of
 // Computes how many bytes you'd have to pad to be able to write an
 // "scalar_size" scalar if the buffer had grown to "buf_size" (downwards in
 // memory).
+__supress_ubsan__("unsigned-integer-overflow")
 inline size_t PaddingBytes(size_t buf_size, size_t scalar_size) {
   return ((~buf_size) + 1) & (scalar_size - 1);
 }