Feature - UpgradeableLoaderInstruction::ExtendProgramChecked

[Lichtso]

See SIMD-0164.

Feature Gate Issue: TODO

[mergify]

The Firedancer team maintains a line-for-line reimplementation of the
native programs, and until native programs are moved to BPF, those
implementations must exactly match their Agave counterparts.
If this PR represents a change to a native program implementation (not
tests), please include a reviewer from the Firedancer team. And please
keep refactors to a minimum.

[Lichtso]

SIMD was retracted.