Fixes broken builds for GCC5 and CLANG38 with RDTSC_CANARY_ENABLE

Some firmware implementations may provide an empty Memory Attributes
Table (NumberOfEntries is zero). Avoid calling OcUpdateDescriptors in
this case, as it will lead to division by zero.

This resolves boot failures due to #DE on XPS 15 9560 when Secure Boot
is enabled.

(Apparently changed requirements here since VMware 12 &/or Big Sur:
https://communities.vmware.com/t5/VMware-Fusion-Discussions/GDB-Stub-breakpoints-not-triggering-on-MacOS-guest/m-p/2850864 )

OcBootManagementLib: Extend ProtectUefiServices quirk to restore hooks overwritten by GRUB2 shim as required

Thanks @perez987 for notifying

Makes it easier for end users to realise that e.g. invalid NVRAM contents can cause failures here

This resolves verbose output issues on ASUS Z690F.

https://github.com/acidanthera/bugtracker/issues/1702

closes acidanthera/bugtracker#1717

This fixes fs-relative access in OpenRuntime killing Windows

Discovered on Windows PowerShell. Fixed by adding spaces at the end of the string.