More exciting bug-fixes:

• linux: Fix ProcMapsEntry major/minor number parsing. Thanks @chouex!
• interceptor: Fix ARMv8 BTI interoperability. Thanks @zjw88282740!
• arm64-writer: Add put_ret_reg(). Thanks @zjw88282740!
• compiler: Fix filesystem access on some Linux systems, e.g. Ubuntu 20.04. Kudos to @pancake for reporting and helping track this one down!