Optimize global variable lists

Reduce binary size by storing global variable lists as one long string
instead of as an array of pointers to strings.

This might also reduce load times (due to fewer relocations and less
pointer chasing), but I haven't measured.

    platform        | before | after
    ----------------+--------+------
    darwin-x64.node | 826K   | 826K
    linux-x64.node  | 818K   | 782K
    win32-ia32.node | 486K   | 479K
    win32-x64.node  | 670K   | 656K

Author: strager

src/configuration.cpp

@@ -30,18 +30,19 @@ const global_declared_variable_set& configuration::globals() noexcept {
     return this->globals_;
   }
 
-  auto add_globals = [&](const char8* const* group_globals, bool shadowable,
+  auto add_globals = [&](const char8* group_globals, bool shadowable,
                          bool writable) -> void {
     if (!group_globals) {
       return;
     }
-    for (const char8* const* it = group_globals; *it; ++it) {
-      string8_view global(*it);
+    for (const char8* it = group_globals; *it != '\0';) {
+      string8_view global(it);
       if (!this->should_remove_global_variable(global)) {
         global_declared_variable* var = this->globals_.add_variable(global);
         var->is_shadowable = shadowable;
         var->is_writable = writable;
       }
+      it += global.size() + 1;
     }
   };
   for (std::size_t i = 0; i < this->enabled_global_groups_.size(); ++i) {