builtin: add .nogrow and .nofree flags to array (#16661)

vlib/builtin/array_shrinkage_test.v

@@ -1,57 +0,0 @@
-fn show_array(name string, a []int) {
-	eprintln('${name:10} .flags: ${a.flags:34} | .cap: ${a.cap:2} | .len: ${a.len:2} | .data: ${a.data} | ${a}')
-}
-
-fn trace_delete_elements(name string, mut a []int) int {
-	a.delete_many(5, 3)
-	show_array(name, a)
-	a << 55
-	show_array(name, a)
-	a << 66
-	show_array(name, a)
-	a << 77
-	res := a.cap
-	eprintln('                                        <<   ${name:10} .cap: ${a.cap} >>')
-	show_array(name, a)
-	a << 88
-	show_array(name, a)
-	a << 99
-	show_array(name, a)
-	eprintln('-------------------------------')
-	return res
-}
-
-fn test_array_cap_shrinkage_after_deletion() {
-	mut a := [0]
-	mut middle_cap := 0
-
-	a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
-	middle_cap = trace_delete_elements('normal', mut a)
-	assert middle_cap == 14
-	assert a.len == 12
-	assert a.cap == 14
-
-	a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
-	unsafe { a.flags.set(.noslices) }
-	middle_cap = dump(trace_delete_elements('noslices', mut a))
-	assert middle_cap == 14
-	assert a.len == 12
-	assert a.cap == 14
-
-	a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
-	unsafe { a.flags.set(.noshrink) }
-	middle_cap = dump(trace_delete_elements('noshrink', mut a))
-	assert middle_cap == 14
-	assert a.len == 12
-	assert a.cap == 14
-
-	// Note: when *both* flags are set, the memory block for the array
-	// should NOT shrink on deleting array elements, thus << after the
-	// deletion, will still have space (till .cap is reached).
-	a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
-	unsafe { a.flags.set(.noslices | .noshrink) }
-	middle_cap = dump(trace_delete_elements('both', mut a))
-	assert middle_cap == 10
-	assert a.len == 12
-	assert a.cap == 20
-}