Revert "Reland "[lldb] Remove non address bits when looking up memory regions""
This reverts commit fac3f20de55769d028bd92220e74f22fa57dd4b2.
I found this has broken how we detect the last memory region in
GetMemoryRegions/"memory region" command.
When you're debugging an AArch64 system with pointer authentication,
the ABI plugin will remove the top bit from the end address of the last
user mapped area.
[0x0000fffffffdf000-0x0001000000000000) rw- [stack]
ABI plugin removes anything above the 48th bit (48 bit virtual addresses
by default on AArch64, leaving an address of 0.
You get back a mapping for 0 and get into an infinite loop.