Eagerly name modules and classes

* variable.c: make the hidden ivars `classpath` and `tmp_classpath` the source
  of truth for module and constant names. Assign to them when modules are bind
  to constants.

* variable.c: remove references to module name cache, as what used to be the cache
  is now the source of truth. Remove rb_class_path_no_cache().

* variable.c: remove the hidden ivar `classid`. This existed for the purposes of
  module name search, which is now replaced. Also, remove the associated
  rb_name_class().

* class.c: use rb_set_class_path_string to set the name of Object during boot.
  Must use a fstring as this runs before rb_cString is initialized and
  creating a normal string leads to a VALUE without a class.

* spec/ruby/core/module/name_spec.rb: add a few specs to specify what happens
  to Module#name across multiple operations. These specs pass without other
  code changes in this commit.

[Feature #15765]

1 files changed, 1 insertions, 4 deletions

diff --git a/class.c b/class.c
index 0cee5caae2..6c71ec8bd0 100644
--- a/class.c
+++ b/class.c
@@ -537,7 +537,6 @@ boot_defclass(const char *name, VALUE super)
     VALUE obj = rb_class_boot(super);
     ID id = rb_intern(name);
 
-    rb_name_class(obj, id);
     rb_const_set((rb_cObject ? rb_cObject : obj), id, obj);
     rb_vm_add_root_module(id, obj);
     return obj;
@@ -551,7 +550,7 @@ Init_class_hierarchy(void)
     rb_gc_register_mark_object(rb_cObject);
 
     /* resolve class name ASAP for order-independence */
-    rb_class_name(rb_cObject);
+    rb_set_class_path_string(rb_cObject, rb_cObject, rb_fstring_lit("Object"));
 
     rb_cModule = boot_defclass("Module", rb_cObject);
     rb_cClass =  boot_defclass("Class",  rb_cModule);
@@ -669,7 +668,6 @@ rb_define_class(const char *name, VALUE super)
     }
     klass = rb_define_class_id(id, super);
     rb_vm_add_root_module(id, klass);
-    rb_name_class(klass, id);
     rb_const_set(rb_cObject, id, klass);
     rb_class_inherited(super, klass);
 
@@ -767,7 +765,6 @@ rb_define_module_id(ID id)
     VALUE mdl;
 
     mdl = rb_module_new();
-    rb_name_class(mdl, id);
 
     return mdl;
 }