Revert ""Reland "[hwasan] Provide aliases for c allocation functions for Fuchsia""

This reverts commit 39ece758.

Reverting because I suspect this is leading to the failures we see in
fxbug.dev/125426. We're seeing unexpected OOMs and I suspect it's
because this change makes c-style allocation functions use hwasan's
allocator which might be worse than the default one (scudo). Reverting
for now to see if this unblocks the clang roll.