Revert "Re-export libgcc's __aeabi_uidivmod and __popcount_tab"

This reverts commit 2ee6baa337c374b273a21caa8472264f64a64690.
Revert "Add __popcountsi2 to the function compat list."

This reverts commit 605a77d250cb2a23177b9bb24c0f1fbf1ddd9120.
Revert "[ARM NEON] libm: original optimized modf"

This reverts commit eb10e8a6063ac5134e036749596e9457755a1a05.