In-place ops deadlock when operands share the same storage

[zackangelo]

In InPlaceOp2, we must acquire a write lock on the lhs tensor's storage and a read lock on the rhs tensor's storage. Because Rust's RwLock is not reentrant, this results in a deadlock when both tensors share the same storage (e.g., are narrowed views into a larger tensor).

candle/candle-core/src/custom_op.rs

Lines 361 to 364 in 9ede204

	pub fn inplace_op2<C: InplaceOp2>(&self, rhs: &Self, c: &C) -> Result<()> {
	self.storage_mut()
	.inplace_op2(self.layout(), &rhs.storage(), rhs.layout(), c)
	}