`get_runtime_isa()` has been deprecated for some time. It is a leftover
piece of code from when gem5 was compiled to a single ISA and that ISA
used to configure the simulated system to use that ISA. Since multi-ISA
compilations are possible, `get_runtime_isa()` should not be used.
Unless the gem5 binary is compiled to a single ISA, a failure will
occur.
The new proceedure for specify which ISA to use is by the setting of the
correct `BaseCPU` implementation. E.g., `X86SimpleTimingCPU` of
`ArmO3CPU`.
This patch removes the remaining `get_runtime_isa()` instances and
removes the function itself. The `SimpleCore` class has been updated to
allow for it's CPU factory to return a class, needed by scripts in
"configs/common".
The deprecated functionality in the standard library, which allowed for
the specifying of an ISA when setting up a processor and/or core has
also been removed. Setting an ISA is now manditory.
Fixes#216.