[llvm] [GlobalIsel][NFC] Refactor ext of trunc (PR #92533)

[Jay Foad via llvm-commits]

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@@ -735,18 +735,20 @@ def redundant_sext_inreg: GICombineRule <
 // the destination type.
 def anyext_trunc_fold: GICombineRule <
   (defs root:$root, register_matchinfo:$matchinfo),
-  (match (wip_match_opcode G_ANYEXT):$root,
-         [{ return Helper.matchCombineAnyExtTrunc(*${root}, ${matchinfo}); }]),
-  (apply [{ Helper.replaceSingleDefInstWithReg(*${root}, ${matchinfo}); }])
+  (match (G_TRUNC $input, $x),
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jayfoad wrote:

Does this still match if there is a G_ASSERT_ZEXT in between? If so, how? If not, why doesn't it regress the tests added in #74125?

https://github.com/llvm/llvm-project/pull/92533