Fix incremental parsing problem with non-terminal extras

Also add PHP grammar as a fixture to test against.

cli/src/tests/corpus_test.rs

@@ -22,6 +22,7 @@ const LANGUAGES: &'static [&'static str] = &[
     "html",
     "javascript",
     "json",
+    "php",
     "python",
 ];
 

lib/src/parser.c

@@ -324,6 +324,8 @@ static bool ts_parser__can_reuse_first_leaf(
   TSStateId leaf_state = ts_subtree_leaf_parse_state(tree);
   TSLexMode leaf_lex_mode = self->language->lex_modes[leaf_state];
 
+  if (current_lex_mode.lex_state == (uint16_t)(-1)) return false;
+
   // If the token was created in a state with the same set of lookaheads, it is reusable.
   if (
     table_entry->action_count > 0 &&

script/fetch-fixtures

@@ -30,6 +30,7 @@ fetch_grammar html              master
 fetch_grammar javascript        master
 fetch_grammar jsdoc             master
 fetch_grammar json              master
+fetch_grammar php               master
 fetch_grammar python            master
 fetch_grammar ruby              master
 fetch_grammar rust              master

script/fetch-fixtures.cmd

@@ -9,6 +9,7 @@ call:fetch_grammar html              master
 call:fetch_grammar javascript        master
 call:fetch_grammar jsdoc             master
 call:fetch_grammar json              master
+call:fetch_grammar php               master
 call:fetch_grammar python            master
 call:fetch_grammar ruby              master
 call:fetch_grammar rust              master