[llvm] [mlir] [MLGO] Do not hardcode 33 eviction feature columns (PR #224598)

[Arseniy Obolenskiy via llvm-commits]

================
@@ -24,7 +24,8 @@
 ]
 """
 PER_REGISTER_FEATURE_LIST = ["mask"]
-NUM_REGISTERS = 33
+# Must match getRequiredNumColumns() for the target the tests run on (X86).
+NUM_REGISTERS = 37
----------------
aobolensk wrote:

Probably, 37 is not correct, but it is something that is returned by the existing fuctionality 

https://github.com/llvm/llvm-project/pull/224598