Bug 1849874 - Update from packed_simd_2 to packed_simd. (ESR version) a=pascalc

third_party/rust/packed_simd/ci/runtest-android.rs

third_party/rust/packed_simd/ci/setup_benchmarks.sh

third_party/rust/packed_simd/ci/test-runner-linux

third_party/rust/packed_simd/contributing.md

third_party/rust/packed_simd/perf-guide/.gitignore

third_party/rust/packed_simd/perf-guide/book.toml

third_party/rust/packed_simd/perf-guide/src/SUMMARY.md

third_party/rust/packed_simd/perf-guide/src/ascii.css

third_party/rust/packed_simd/perf-guide/src/bound_checks.md

...arty/rust/packed_simd/perf-guide/src/float-math/approx.md

...d_party/rust/packed_simd/perf-guide/src/float-math/fma.md

third_party/rust/packed_simd/perf-guide/src/float-math/fp.md

..._party/rust/packed_simd/perf-guide/src/float-math/svml.md

third_party/rust/packed_simd/perf-guide/src/introduction.md

third_party/rust/packed_simd/perf-guide/src/prof/linux.md

third_party/rust/packed_simd/perf-guide/src/prof/mca.md

...d_party/rust/packed_simd/perf-guide/src/prof/profiling.md

...st/packed_simd/perf-guide/src/target-feature/attribute.md

...ust/packed_simd/perf-guide/src/target-feature/features.md

...ust/packed_simd/perf-guide/src/target-feature/inlining.md