Imported Upstream version 5.18.0.246

Former-commit-id: 0c7ce5b1a7851e13f22acfd379b7f9fb304e4833

external/llvm/test/TableGen/Tree.td

@@ -0,0 +1,19 @@
+// This tests to make sure we can parse tree patterns.
+// RUN: llvm-tblgen %s
+// XFAIL: vg_leak
+
+class TreeNode;
+class RegisterClass;
+
+def set  : TreeNode;
+def plus : TreeNode;
+def imm  : TreeNode;
+def R32  : RegisterClass;
+
+class Inst<dag T> {
+  dag Pattern = T;
+}
+
+def ADDrr32 : Inst<(set R32, (plus R32, R32))>;  // a = b + c
+def ADDri32 : Inst<(set R32, (plus R32, imm))>;  // a = b + imm
+