Change parser_token_types from wcstring to const wchar_t *

Reduces allocations and startup time

src/fish_indent.cpp

@@ -104,7 +104,7 @@ static void dump_node(indent_t node_indent, const parse_node_t &node, const wcst
     }
     fwprintf(stderr, L"{off %4d, len %4d, indent %2u, %ls} [%ls|%ls|%ls]\n",
             node.source_start, node.source_length, node_indent,
-            parser_token_types[node.type].c_str(), prevc_str, source.substr(node.source_start,
+            parser_token_types[node.type], prevc_str, source.substr(node.source_start,
             node.source_length).c_str(), nextc_str);
 }
 

src/parse_constants.h

@@ -83,7 +83,7 @@ enum parse_token_type_t
     LAST_PARSE_TOKEN_TYPE = parse_token_type_end
 } __packed;
 // Array of strings corresponding to the enums above instantiated in parse_tree.cpp.
-extern wcstring parser_token_types[];
+extern const wchar_t * const parser_token_types[];
 
 /* These must be maintained in sorted order (except for none, which isn't a keyword). This enables us to do binary search. */
 enum parse_keyword_t

src/parse_tree.cpp

@@ -17,7 +17,7 @@
 #include <algorithm>
 
 // This array provides strings for each symbol in enum parse_token_type_t in parse_constants.h.
-wcstring parser_token_types[] = {
+const wchar_t * const parser_token_types[] = {
     L"token_type_invalid",
     L"symbol_job_list",
     L"symbol_job",