MJIT: Refactor CDHASH handling

Converting a CDHASH into a safe Hash is a lot of work, but retrieving
just values is much easier.

lib/mjit/compiler.rb

@@ -544,12 +544,12 @@ class RubyVM::MJIT::Compiler
       when /\A\s+JUMP\((?<dest>[^)]+)\);\s+\z/
         dest = Regexp.last_match[:dest]
         if insn.name == :opt_case_dispatch # special case... TODO: use another macro to avoid checking name
+          hash_offsets = C.rb_hash_values(operands[0])
           else_offset = cast_offset(operands[1])
-          cdhash = C.cdhash_to_hash(operands[0])
           base_pos = pos + insn_len
 
           src << "    switch (#{dest}) {\n"
-          cdhash.each do |_key, offset|
+          hash_offsets.each do |offset|
             src << "      case #{offset}:\n"
             src << "        goto label_#{base_pos + offset};\n"
           end

mjit_c.rb

@@ -5,8 +5,8 @@ module RubyVM::MJIT
   # This `class << C` section is for calling C functions. For importing variables
   # or macros as is, please consider using tool/mjit/bindgen.rb instead.
   class << C
-    def cdhash_to_hash(cdhash_addr)
-      Primitive.cdhash_to_hash(cdhash_addr)
+    def rb_hash_values(cdhash_addr)
+      Primitive.cexpr! 'rb_hash_values((VALUE)NUM2PTR(cdhash_addr))'
     end
 
     def builtin_compiler(f, bf, index, stack_size, builtin_inline_p)

mjit_compiler.c

@@ -27,12 +27,6 @@
 #include "insns.inc"
 #include "insns_info.inc"
 
-struct case_dispatch_var {
-    FILE *f;
-    unsigned int base_pos;
-    VALUE last_value;
-};
-
 // Returns true if call cache is still not obsoleted and vm_cc_cme(cc)->def->type is available.
 static bool
 has_valid_method_type(CALL_CACHE cc)
@@ -52,37 +46,6 @@ fastpath_applied_iseq_p(const CALL_INFO ci, const CALL_CACHE cc, const rb_iseq_t
         && vm_call_iseq_optimizable_p(ci, cc); // CC_SET_FASTPATH condition
 }
 
-#define hidden_obj_p(obj) (!SPECIAL_CONST_P(obj) && !RBASIC(obj)->klass)
-
-// TODO: Share this with iseq.c
-static inline VALUE
-obj_resurrect(VALUE obj)
-{
-    if (hidden_obj_p(obj)) {
-        switch (BUILTIN_TYPE(obj)) {
-          case T_STRING:
-            obj = rb_str_resurrect(obj);
-            break;
-          case T_ARRAY:
-            obj = rb_ary_resurrect(obj);
-            break;
-          case T_HASH:
-            obj = rb_hash_resurrect(obj);
-            break;
-          default:
-            break;
-        }
-    }
-    return obj;
-}
-
-static int
-cdhash_each(VALUE key, VALUE value, VALUE hash)
-{
-    rb_hash_aset(hash, obj_resurrect(key), value);
-    return ST_CONTINUE;
-}
-
 #include "mjit_compile_attr.inc"
 
 #if SIZEOF_LONG == SIZEOF_VOIDP
@@ -120,14 +83,6 @@ mjit_compile(FILE *f, const rb_iseq_t *iseq, const char *funcname, int id)
 // Primitive.methods
 //
 
-static VALUE
-cdhash_to_hash(rb_execution_context_t *ec, VALUE self, VALUE cdhash_addr)
-{
-    VALUE hash = rb_hash_new();
-    rb_hash_foreach((VALUE)NUM2PTR(cdhash_addr), cdhash_each, hash);
-    return hash;
-}
-
 static VALUE
 builtin_compile(rb_execution_context_t *ec, VALUE self, VALUE buf, VALUE bf_addr, VALUE index, VALUE stack_size, VALUE builtin_inline_p)
 {