Migrate 'within_fish_init' to a parser-local variable

We need special handling when reporting backtraces for commands run
during startup, i.e. config.fish. Previously we had a global variable;
make it local to the parser to eliminate a global.

No functional change here.

src/fish.cpp

@@ -233,9 +233,10 @@ static void source_config_in_directory(parser_t &parser, const wcstring &dir) {
     FLOGF(config, L"sourcing %ls", escaped_pathname.c_str());
 
     const wcstring cmd = L"builtin source " + escaped_pathname;
-    set_is_within_fish_initialization(true);
+
+    parser.libdata().within_fish_init = true;
     parser.eval(cmd, io_chain_t());
-    set_is_within_fish_initialization(false);
+    parser.libdata().within_fish_init = false;
 }
 
 /// Parse init files. exec_path is the path of fish executable as determined by argv[0].
@@ -426,6 +427,7 @@ int main(int argc, char **argv) {
     set_main_thread();
     setup_fork_guards();
     signal_unblock_all();
+
     setlocale(LC_ALL, "");
 
     // struct stat tmp;

src/parser.cpp

@@ -341,7 +341,7 @@ static void append_block_description_to_stack_trace(const parser_t &parser, cons
         if (file) {
             append_format(trace, _(L"\tcalled on line %d of file %ls\n"), b.src_lineno,
                           user_presentable_path(file, parser.vars()).c_str());
-        } else if (is_within_fish_initialization()) {
+        } else if (parser.libdata().within_fish_init) {
             append_format(trace, _(L"\tcalled during startup\n"));
         }
     }
@@ -493,7 +493,7 @@ wcstring parser_t::current_line() {
         if (file) {
             append_format(prefix, _(L"%ls (line %d): "),
                           user_presentable_path(file, vars()).c_str(), lineno);
-        } else if (is_within_fish_initialization()) {
+        } else if (libdata().within_fish_init) {
             append_format(prefix, L"%ls (line %d): ", _(L"Startup"), lineno);
         } else {
             append_format(prefix, L"%ls (line %d): ", _(L"Standard input"), lineno);

src/parser.h

@@ -152,6 +152,9 @@ struct library_data_t {
     /// Number of recursive calls to the internal completion function.
     uint32_t complete_recursion_level{0};
 
+    /// If set, we are currently within fish's initialization routines.
+    bool within_fish_init{false};
+
     /// If we're currently repainting the commandline.
     /// Useful to stop infinite loops.
     bool is_repaint{false};

src/proc.h

@@ -563,12 +563,6 @@ void proc_init();
 /// Wait for any process finishing, or receipt of a signal.
 void proc_wait_any(parser_t &parser);
 
-/// Set and get whether we are in initialization.
-// Hackish. In order to correctly report the origin of code with no associated file, we need to
-// know whether it's run during initialization or not.
-void set_is_within_fish_initialization(bool flag);
-bool is_within_fish_initialization();
-
 /// Send SIGHUP to the list \p jobs, excepting those which are in fish's pgroup.
 void hup_jobs(const job_list_t &jobs);