[llvm] [AArch64] Use GISel for optnone functions (PR #174746)

[Matt Arsenault via llvm-commits]

================
@@ -503,9 +503,14 @@ MachineFunction::CreateMachineBasicBlock(const BasicBlock *BB,
           MachineBasicBlock(*this, BB);
   // Set BBID for `-basic-block-sections=list` and `-basic-block-address-map` to
   // allow robust mapping of profiles to basic blocks.
-  if (Target.Options.BBAddrMap ||
-      Target.getBBSectionsType() == BasicBlockSection::List)
-    MBB->setBBID(BBID.has_value() ? *BBID : UniqueBBID{NextBBID++, 0});
+  if ((Target.Options.BBAddrMap ||
+       Target.getBBSectionsType() == BasicBlockSection::List)) {
+    if (BBID)
+      MBB->setBBID(*BBID);
+    else if (BB)
----------------
arsenm wrote:

I'm still not sure about this part. I'm not sure what these "BBIDs" are about, or when they are set. You can have MachineBasicBlocks that do not have a corresponding IR BasicBlock, are those supposed to have IDs assigned?

https://github.com/llvm/llvm-project/pull/174746