[llvm] Avoid undefined behavior in shift operators during constant folding of DIExpressions. (PR #116466)

[Thorsten Schütt via llvm-commits]

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@@ -59,12 +59,14 @@ foldOperationIfPossible(uint64_t Const1, uint64_t Const2,
     return Const1 - Const2;
   }
   case dwarf::DW_OP_shl: {
-    if ((uint64_t)countl_zero(Const1) < Const2)
+    if (Const2 >= std::numeric_limits<uint64_t>::digits ||
+        (uint64_t)countl_zero(Const1) < Const2)
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tschuett wrote:

Drive-by nit: named casts are preferred, i.e., static_cast.

https://github.com/llvm/llvm-project/pull/116466