sim: Don't needlessly recreate ISA types in InstRecord.
sim: Don't needlessly recreate ISA types in InstRecord.

The ISAs already define fully realized types. We don't need to
separately track what parameters they used and then feed them into the
same templates again elsewhere.

Change-Id: Iac18bb9374ff684259c6aa00036eac4d1026dcfc
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/42002
Reviewed-by: Giacomo Travaglini <8eef13a4f970e2e9372c8d26ad0737b760f99c02@arm.com>
Maintainer: Giacomo Travaglini <8eef13a4f970e2e9372c8d26ad0737b760f99c02@arm.com>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5