9164ea7032
When LDP uses a negative offset (which it valid), since
`struct ir3_register` uses `{i,u}nt32_t` for the immediate
values, using `extract_reg_uim()` wasn't sign extending
negative immediate values.
Addresses:
```
src/freedreno/isa/encode.h:84:
pack_field: Assertion '!(( val & ~BITFIELD64_MASK(1 + high - low)) &&
(~val & ~BITFIELD64_MASK(1 + high - low)))' failed.
```
seen in https://gitlab.freedesktop.org/mesa/mesa/-/issues/11153 .
Signed-off-by: Karmjit Mahil <karmjit.mahil@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29768>