Revert "[GlobalISel][AArch64] Add selection support for G_EXTRACT_VECTOR_ELT"

This broke test-suite::aarch64_neon_intrinsics.test

Reverting while I look into it.

Example failure:
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-quick/builds/17740

llvm-svn: 355408