Fix for unsigned integer overflow:

Error Message: BufferWriter.cpp:76:16: runtime error: unsigned integer overflow: 0 - 1 cannot be represented in type 'size_t' (aka 'unsigned long')

when size becomes 0 and we are in while (size-- > 0), then size will become less than 0, which should be avoided since it is an unsigned (although technically it wraps around, UBSAN complains about it).
Fix: stop size from decrement past 0, by moving size-- inside the loop

src/lib/support/BufferWriter.cpp

@@ -73,17 +73,19 @@ LittleEndian::BufferWriter & LittleEndian::BufferWriter::EndianPutSigned(int64_t
 
 BigEndian::BufferWriter & BigEndian::BufferWriter::EndianPut(uint64_t x, size_t size)
 {
-    while (size-- > 0)
+    while (size > 0)
     {
+        size--;
         Put(static_cast<uint8_t>((x >> (size * 8)) & 0xff));
     }
     return *this;
 }
 
 BigEndian::BufferWriter & BigEndian::BufferWriter::EndianPutSigned(int64_t x, size_t size)
 {
-    while (size-- > 0)
+    while (size > 0)
     {
+        size--;
         Put(static_cast<uint8_t>((x >> (size * 8)) & 0xff));
     }
     return *this;