[llvm] [X86] Check for AMXTile (PR #136507)

[Simon Pilgrim via llvm-commits]

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@@ -75,6 +75,8 @@ bool X86LowerTileCopy::runOnMachineFunction(MachineFunction &MF) {
     return false;
 
   const X86Subtarget &ST = MF.getSubtarget<X86Subtarget>();
+  if (!ST.hasAMXTILE())
+    return false;
----------------
RKSimon wrote:

at the very most you should just need to assert here:
```assert(ST.hasAMXTILE() && "Only supported on AMXTILE targets");```

https://github.com/llvm/llvm-project/pull/136507