Revert "std.valgrind: add helgrind functions"

This reverts commit f2ab9512af0154a291ce11ab0a1298fbf778d751.

I did it wrong and didn't end up using these.
87e4f7376aAndrew Kelley committed on 12/24/2020, 8:14:41 AMparentc2b1c88
1 file changedLine totals unavailable