Implemented missing move/exchange paths for x86

Rationale:
Recent SIMD register spilling bug fix exposed missing
cases in the x86 and x86_64 code generator for moving
and exchanging SIMD spill slots.

Test: run-test --host  -Xcompiler-option --instruction-set-features=sse4.1 623-checker-loop-regressions (32/64)

Bug: 70559970
Change-Id: Iae66d6874b93af5b2db80db70bce4b0f4a9b9f3f