Reading binary by loadMemoryFromFile() causes MalformedInputException

[learning-chip]

Type of issue: bug report
Impact: no functional change
Development Phase: request

If the current behavior is a bug, please provide the steps to reproduce the problem:

This call:

loadMemoryFromFile(mem, fileName, MemoryLoadFileType.Binary)

causes error:

java.nio.charset.MalformedInputException: Input length = 1

However, the same binary can be loaded by java.nio.file.Files.readAllBytes without problems.

Complete code to reproduce error: https://gist.github.com/learning-chip/07007f5a6c8f0c69f85d806e89756f85
Instruction binary is generated by: https://gist.github.com/learning-chip/f3d00568437ef5e2541c0ea6ac792a1d
Both can run in the online notebook at https://github.com/freechipsproject/chisel-bootcamp

Please tell us about your environment:
Chisel v3.4.2
chiseltest v0.3.2