ocaml-tree-sitter-semgrep

Fix the Semgrep extension grammar for a language until `test-lang <lang>` passes. Use when the semgrep grammar build/test fails — typically after an upstream tree-sitter grammar was bumped: parser-generation errors, corpus mismatches, failed example files, or Blank-node warnings under `lang/semgrep-grammars/src/semgrep-<lang>/`. Edits only this repo's semgrep grammar/tests; never the upstream submodule or the CST→AST translation.