#[unsafe(no_mangle)]pub extern "C" fn jit_arc_string_retain(bits: u64)Expand description
Retain (clone) an Arc<String> strong-count share. Bumps the standard
Rust Arc refcount at offset -16 of the Arc::into_raw pointer via
Arc::increment_strong_count::<String> — NOT the W-series
UnifiedValue<T> refcount at offset 4 (jit_arc_retain’s shape).
SAFETY: bits must be Arc::into_raw(Arc<String>) as u64 produced by
the MirConstant::Str / MirConstant::StringId lowering in
mir_compiler/ownership.rs::compile_constant, or by the VM-side
KindedSlot::from_string_arc producer. Null is silently no-op’d
(mirror of Round 7A’s jit_arc_result_retain null-bits safety).