load.c: use fstring instead of OBJ_FREEZE

These strings already exist (or will exist soon) in the fstring
table, so avoid the duplicate, sooner.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62030 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

encoding.c

@@ -661,7 +661,7 @@ load_encoding(const char *name)
 	++s;
     }
     FL_UNSET(enclib, FL_TAINT);
-    OBJ_FREEZE(enclib);
+    enclib = rb_fstring(enclib);
     ruby_verbose = Qfalse;
     ruby_debug = Qfalse;
     errinfo = rb_errinfo();
@@ -1162,8 +1162,7 @@ enc_names_i(st_data_t name, st_data_t idx, st_data_t args)
     VALUE *arg = (VALUE *)args;
 
     if ((int)idx == (int)arg[0]) {
-	VALUE str = rb_usascii_str_new2((char *)name);
-	OBJ_FREEZE(str);
+	VALUE str = rb_fstring_cstr((char *)name);
 	rb_ary_push(arg[1], str);
     }
     return ST_CONTINUE;
@@ -1697,8 +1696,7 @@ rb_enc_aliases_enc_i(st_data_t name, st_data_t orig, st_data_t arg)
 	str = rb_fstring_cstr(rb_enc_name(enc));
 	rb_ary_store(ary, idx, str);
     }
-    key = rb_usascii_str_new2((char *)name);
-    OBJ_FREEZE(key);
+    key = rb_fstring_cstr((char *)name);
     rb_hash_aset(aliases, key, str);
     return ST_CONTINUE;
 }