allow string interpolation in symbols like :"a=#{15}"

src/codegen.c

@@ -1711,6 +1711,15 @@ codegen(codegen_scope *s, node *tree, int val)
     }
     break;
 
+  case NODE_DSYM:
+    codegen(s, tree, val);
+    if (val) {
+      pop();
+      genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern(s->mrb, "intern")), 0));
+      push();
+    }
+    break;
+
   case NODE_SELF:
     if (val) {
       genop(s, MKOP_A(OP_LOADSELF, cursp()));

src/parse.y

@@ -527,13 +527,6 @@ new_strsym(parser_state *p, node* str)
   return mrb_intern2(p->mrb, s, len);
 }
 
-// (:sym . a)
-static node*
-new_dsym(parser_state *p, node *a)
-{
-  return cons((node*)NODE_DSYM, a);
-}
-
 // (:lvar . a)
 static node*
 new_lvar(parser_state *p, mrb_sym sym)
@@ -705,6 +698,13 @@ new_dstr(parser_state *p, node *a)
   return cons((node*)NODE_DSTR, a);
 }
 
+// (:dsym . a)
+static node*
+new_dsym(parser_state *p, node *a)
+{
+  return cons((node*)NODE_DSYM, new_dstr(p, a));
+}
+
 // (:backref . n)
 static node*
 new_back_ref(parser_state *p, int n)