Use cheaper init in thread_local (rust-lang/backtrace-rs#701)
`thread_local!` has special case for `const {}` syntax, and avoids creating an extra lazy init function in such case.diff --git a/src/lib.rs b/src/lib.rs
index ab5e64c..1377509 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -150,7 +150,7 @@
static mut LOCK: *mut Mutex<()> = ptr::null_mut();
static INIT: Once = Once::new();
// Whether this thread is the one that holds the lock
- thread_local!(static LOCK_HELD: Cell<bool> = Cell::new(false));
+ thread_local!(static LOCK_HELD: Cell<bool> = const { Cell::new(false) });
impl Drop for LockGuard {
fn drop(&mut self) {
