[AsmPrinter][TLOF] Reintroduce AArch64 test

Follow up from r231505.

Fix the non-determinism by using a MapVector and reintroduce the AArch64
testcase. Defer deleting the got candidates up to the end and remove
them in a bulk, avoiding linear time removal of each element.

Thanks to Renato Golin for trying it out on other platforms.

llvm-svn: 231830