[llvm] Introduce DIExpression::foldConstantMath() (PR #71718)

[Paul T Robinson via llvm-commits]

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@@ -3120,6 +3120,285 @@ TEST_F(DIExpressionTest, get) {
   EXPECT_EQ(N0WithPrependedOps, N2);
 }
 
+TEST_F(DIExpressionTest, Fold) {
+
+  // Remove a No-op DW_OP_plus_uconst from an expression.
+  SmallVector<uint64_t, 8> Ops = {dwarf::DW_OP_plus_uconst, 0};
+  auto *Expr = DIExpression::get(Context, Ops);
+  auto *E = Expr->foldConstantMath();
+  SmallVector<uint64_t, 8> ResOps;
+  auto *ResExpr = DIExpression::get(Context, ResOps);
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pogo59 wrote:

Maybe `EmptyExpr` which you can set up once and not have to keep calling `DIExpression::get` ?

https://github.com/llvm/llvm-project/pull/71718