Reapply "[X86] Use default attributes for even more intrinsics"

Also un-XFAIL a test that now passes.

Fixes SWDEV-422608

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Another followup to D136939: This switches readonly X86 intrinsics
to use default attributes (nosync, nofree, nocallback and willreturn).

With this, all readnone/readonly intrinsics should be covered,
only memory writing intrinsics are left.

Differential Revision: https://reviews.llvm.org/D137552

Change-Id: Ib1e0124ccbbb26b666363be0d9ed77105a5ac1ea

Author: nikic