[lldb] Treat ARM64X images as ARM64.

[jacek]

Summary

With D149091, ARM64X binaries are no longer reported as ARM64. This broke lldb tests as Windows 11 system DLLs are mostly ARM64X binaries and lldb doesn't know how to handle them. Ideally lldb would understand a bit more about ARM64X and handle them as AMD64 in x64 processes, but this is enough to preserve previous behaviour and unbreak tests.

[mstorsjo]

I think this looks good. Did @antmo verify that it actually fixes the issue? (It seems plausible, although there may be more similar cases hiding somewhere?)

After this is landed, we need to make sure to backport this to the newly created 17.x branch.

[antmo]

In D156268#4534366, @mstorsjo wrote:

I think this looks good. Did @antmo verify that it actually fixes the issue? (It seems plausible, although there may be more similar cases hiding somewhere?)

Not yet. Struggling a bit with the windows setup

[antmo]

I confirm that the 7 failed tests are now Ok

[jacek]

Thanks for review and testing. I created https://github.com/llvm/llvm-project/issues/64131 for the backport.

lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h

 public:
   enum MachineType {
     MachineUnknown = 0x0,
     MachineAm33 = 0x1d3,
     MachineAmd64 = 0x8664,
     MachineArm = 0x1c0,
     MachineArmNt = 0x1c4,
     MachineArm64 = 0xaa64,
+    MachineArm64X = 0xa64e,
     MachineEbc = 0xebc,
     MachineX86 = 0x14c,
     MachineIA64 = 0x200,
     MachineM32R = 0x9041,
     MachineMips16 = 0x266,
     MachineMipsFpu = 0x366,
     MachineMipsFpu16 = 0x466,
     MachinePowerPc = 0x1f0,

lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp

case MachineX86:
     specs.Append(module_spec);
     break;
   case MachineArmNt:
     spec.SetTriple("armv7-pc-windows");
     spec.GetTriple().setEnvironment(env);
     specs.Append(module_spec);
     break;
   case MachineArm64:
+  case MachineArm64X:
     spec.SetTriple("aarch64-pc-windows");
     spec.GetTriple().setEnvironment(env);
     specs.Append(module_spec);
     break;
   default:
     break;
   }