Refactoring: simplify definition of some internal variables.
In some cases, we never specbind internal objects, so they don't have to be symbols. Rather than using DEFSYM/DEFVAR and then uninterning the symbols, use plain static variables. Call staticpro for all of them, to protect them from the garbage collector. * src/eval.c (syms_of_eval): Use a static variable for Qcatch_all_memory_full. * src/emacs-module.c (syms_of_module): Use static variables for Vmodule_refs_hash, Vmodule_runtimes, and Vmodule_environments.