Function patch_seq_symbol_equal 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn patch_seq_symbol_equal(stack: Stack) -> Stack

Compare two symbols for equality

Stack effect: ( Symbol Symbol – Bool )

Optimization (Issue #166): If both symbols are interned (capacity=0), we use O(1) pointer comparison instead of O(n) string comparison.

Safety

Stack must have two Symbol values on top