[AArch64] Make opcode switch in tryARM64PackedUnwind comprehensive.

[efriedma]

Summary

I don't think compiler-generated code could actually be affected by this, but better to be thorough.

[efriedma]

Fix typo

[mstorsjo]

LGTM, thanks!

llvm/lib/MC/MCWin64EH.cpp

1014

In addition to these, there's also UOP_PushMachFrame (which is shared with x86_64) which can be used on arm64, in the same way (only manually generated with custom assembly directives).

The fact that some opcodes are shared between x86_64, arm64 and arm is a bit messy - I guess it would be clearer if they would be entirely separate sets of opcodes without reuse.

llvm/lib/MC/MCWin64EH.cpp

for (const WinEH::Instruction &Inst : info->Instructions) {
     case Win64EH::UOP_SaveAnyRegIPX:
     case Win64EH::UOP_SaveAnyRegDX:
     case Win64EH::UOP_SaveAnyRegDPX:
     case Win64EH::UOP_SaveAnyRegQX:
     case Win64EH::UOP_SaveAnyRegQPX:
       // These are never canonical; they don't show up with the usual Arm64
       // calling convention.
       return false;
+    case Win64EH::UOP_AllocLarge:
+      // Allocations this large can't be represented in packed unwind (and
+      // usually don't fit the canonical form anyway because we need to use
+      // __chkstk to allocate the stack space).
+      return false;
+    case Win64EH::UOP_AddFP:
+      // "add x29, sp, #N" doesn't show up in the canonical pattern (except for
+      // N=0, which is UOP_SetFP).
+      return false;
+    case Win64EH::UOP_TrapFrame:
+    case Win64EH::UOP_Context:
+    case Win64EH::UOP_ClearUnwoundToCall:
+    case Win64EH::UOP_PushMachFrame:
+      // These are special opcodes that aren't normally generated.
+      return false;
+    default:
+      report_fatal_error("Unknown Arm64 unwind opcode");
     }
   }
   if (RegI > 10 || RegF > 8)
     return false;
   if (StandaloneLR && FPLRPair)
     return false;
   if (FPLRPair && Location != End)
     return false;