build(rust): vendor rnix parser crate

third_party/crates/rnix-0.14.0/test_data/parser/success/merge.expect

@@ -0,0 +1,26 @@
+NODE_ROOT@0..14
+  NODE_BIN_OP@0..14
+    NODE_ATTR_SET@0..6
+      TOKEN_L_BRACE@0..1 "{"
+      NODE_ATTRPATH_VALUE@1..5
+        NODE_ATTRPATH@1..2
+          NODE_IDENT@1..2
+            TOKEN_IDENT@1..2 "a"
+        TOKEN_ASSIGN@2..3 "="
+        NODE_LITERAL@3..4
+          TOKEN_INTEGER@3..4 "1"
+        TOKEN_SEMICOLON@4..5 ";"
+      TOKEN_R_BRACE@5..6 "}"
+    TOKEN_UPDATE@6..8 "//"
+    NODE_ATTR_SET@8..14
+      TOKEN_L_BRACE@8..9 "{"
+      NODE_ATTRPATH_VALUE@9..13
+        NODE_ATTRPATH@9..10
+          NODE_IDENT@9..10
+            TOKEN_IDENT@9..10 "b"
+        TOKEN_ASSIGN@10..11 "="
+        NODE_LITERAL@11..12
+          TOKEN_INTEGER@11..12 "2"
+        TOKEN_SEMICOLON@12..13 ";"
+      TOKEN_R_BRACE@13..14 "}"
+