builtin: don't memdup element for `array.pop` (depends on how cgen works) (#13789)

The voidptr returned is immediately dereferenced in cgen so the memory
is copied before the array can be appended to: `*(int*)array_pop(&a)`

vlib/builtin/array.v

@@ -402,12 +402,13 @@ pub fn (mut a array) pop() voidptr {
 	a.len = new_len
 	// Note: a.cap is not changed here *on purpose*, so that
 	// further << ops on that array will be more efficient.
-	return unsafe { memdup(last_elem, a.element_size) }
+	return last_elem
 }
 
 // delete_last efficiently deletes the last element of the array.
 // It does it simply by reducing the length of the array by 1.
 // If the array is empty, this will panic.
+// See also: [trim](#array.trim)
 pub fn (mut a array) delete_last() {
 	// copy pasting code for performance
 	$if !no_bounds_checking ? {