The register was defined as a 64-bit register but the test was written
under the assumption it's a 32-bit register. Furthermore, the hardware
write-enable flag had to be set since all values would otherwise be
overwritten immediately.
The software is now able to create most interrupt combinations of
Section 9.9 of the SystemRDL 2.0 LRM. It supports
stickybit/non-stickybit interrupts, it support posedge, negedge,
bothedge, and level interrupts, and it is able to generate all
surrounding logic.
This commit also fixes a reset-bug that caused registers that were reset
to 0 to be not reset (because 'if not reset_value' will return True if
the 'reset_value' is 0).