arch-vega: Free dest registers in non-memory Load DS insts

Ported from https://gem5-review.googlesource.com/c/public/gem5/+/48019:

Certain DS insts are classfied as Loads, but don't actually go through
the memory pipeline. However, any instruction classified as a load
marks its destination registers as free in the memory pipeline.

Because these instructions didn't use the memory pipeline, they
never freed their destination registers, which led to a deadlock.

This patch explicitly calls the function used to free the destination
registers in the execute() method of those Load instructions that
don't use the memory pipeline.

Change-Id: I8231217a79661ca6acc837b2ab4931b946049a1a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55463
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed