ASSERT Failing asserts in vmareas.c on zero-length munmap

Created by: petrochenkov

If munmap syscall has an argument len == 0, then an empty memory range (start == end) is passed to vmareas.c's binary_search and add_vm_area from pre_system_call and post_system_call respectively.

Those functions have asserts checking that the passed range is well-formed (ASSERT(start < end || end == NULL /* wraparound */); or ASSERT(start < end);) and fire on empty ranges.

Zero-length munmaps should always fail with EINVAL, but for some reason they still happen in Geekbench for Android.