Revert "[sanitizer-coverage] test for -fsanitize-coverage=inline-8bit-counters"

Revert "Mark sancov test as unsupported on Darwin"
Revert "[LSan] Detect dynamic loader by its base address."

This reverts commit r304633.
This reverts commit r304673.
This reverts commit r304632.

Those commit have broken LOTS of ARM/AArch64 bots for two days.

llvm-svn: 304699