Previously lldb was storing them but not restoring them. Meaning that this function:
```
void expr(uint64_t value) {
__asm__ volatile("msr tpidr_el0, %0" ::"r"(value));
}
```
When run from lldb:
```
(lldb) expression expr()
```
Would leave tpidr as `value` instead of the original value of the register.
A check for this scenario has been added to TestAArch64LinuxTLSRegisters.py,
which covers tpidr and the SME excluisve tpidr2 register when it's present.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D156512
6239227172