Stop marking chilled strings as frozen

They were initially made frozen to avoid false positives for cases such
as:

    str = str.dup if str.frozen?

But this may cause bugs and is generally confusing for users.

[Feature #20205]

Co-authored-by: Jean Boussier <[email protected]>

2 files changed, 3 insertions, 1 deletions

diff --git a/yjit/src/codegen.rs b/yjit/src/codegen.rs
index 747fa1769d..f426dd87ca 100644
--- a/yjit/src/codegen.rs
+++ b/yjit/src/codegen.rs
@@ -5611,7 +5611,7 @@ fn jit_rb_str_uplus(
     let recv_opnd = asm.stack_pop(1);
     let recv_opnd = asm.load(recv_opnd);
     let flags_opnd = asm.load(Opnd::mem(64, recv_opnd, RUBY_OFFSET_RBASIC_FLAGS));
-    asm.test(flags_opnd, Opnd::Imm(RUBY_FL_FREEZE as i64));
+    asm.test(flags_opnd, Opnd::Imm(RUBY_FL_FREEZE as i64 | RSTRING_CHILLED as i64));
 
     let ret_label = asm.new_label("stack_ret");
 
diff --git a/yjit/src/cruby_bindings.inc.rs b/yjit/src/cruby_bindings.inc.rs
index d53e630a4a..3a1de5f674 100644
--- a/yjit/src/cruby_bindings.inc.rs
+++ b/yjit/src/cruby_bindings.inc.rs
@@ -697,6 +697,8 @@ pub struct rb_call_data {
     pub ci: *const rb_callinfo,
     pub cc: *const rb_callcache,
 }
+pub const RSTRING_CHILLED: ruby_rstring_private_flags = 32768;
+pub type ruby_rstring_private_flags = u32;
 pub const RHASH_PASS_AS_KEYWORDS: ruby_rhash_flags = 8192;
 pub const RHASH_PROC_DEFAULT: ruby_rhash_flags = 16384;
 pub const RHASH_ST_TABLE_FLAG: ruby_rhash_flags = 32768;