The indexer has an option to index function-local symbols (IndexFunctionLocals in IndexingOptions) but it's not exposed through c-index-test. This patch:
- updates c-index-test core -print-source-symbols to additionally take a -include-locals option to turn this on
- adds a 'Local' symbol property to distinguish function-local symbols from the rest
- adds a 'Parameter' symbol subkind to distinguish params from regular variables
- updates the tests to cover the above