[AArch64] Stop using TargetFlags as RegState for LOADgot (#177411)
The register state flags have been represented using `unsigned`, but we
intend to make this an `enum class` in llvm/llvm-project#177090.
That change has shown there is some strange behaviour in this AArch64
function, which uses operand TargetFlags (usually used for representing
some abstract form of relocation information to clarify global accesses,
also represented with `unsigned`) to initialise the register state flags
(used for representing how the register operand is used by an
instruction). These TargetFlags are always 0 in the tests, so remove the
variable and assignment.
llvm-project
b960ef30 - [AArch64] Stop using TargetFlags as RegState for LOADgot (#177411)
