ci: other mut vlib test fixes

vlib/crypto/aes/aes_cbc.v

@@ -105,7 +105,8 @@ pub fn (mut x AesCbc) decrypt_blocks(mut dst []byte, src []byte) {
 
 	// Loop over all but the first block.
 	for start > 0 {
-		x.b.decrypt(mut (*dst).slice(start, end), mut src.slice(start, end))
+		mut src_chunk := src.slice(start, end)
+		x.b.decrypt(mut (*dst).slice(start, end), mut src_chunk)
 		cipher.xor_bytes(mut (*dst).slice(start, end), (*dst).slice(start, end), src.slice(prev, start))
 
 		end = start
@@ -114,7 +115,8 @@ pub fn (mut x AesCbc) decrypt_blocks(mut dst []byte, src []byte) {
 	}
 
 	// The first block is special because it uses the saved iv.
-	x.b.decrypt(mut (*dst).slice(start, end), mut src.slice(start, end))
+	mut src_chunk := src.slice(start, end)
+	x.b.decrypt(mut (*dst).slice(start, end), mut src_chunk)
 	cipher.xor_bytes(mut (*dst).slice(start, end), (*dst).slice(start, end), x.iv)
 
 

vlib/crypto/rc4/rc4_test.v

@@ -15,7 +15,7 @@ fn test_crypto_rc4() {
 	mut src := 'toencrypt'.bytes()
 	
 	// src & dst same, encrypt in place
-	c.xor_key_stream(mut src, src) // encrypt data
+	c.xor_key_stream(mut src, mut src) // encrypt data
 	
 	c.reset()
 

vlib/os/os_test.v

@@ -165,7 +165,7 @@ fn test_write_and_read_bytes() {
 	assert rbytes == payload
 	// check that trying to read data from EOF doesn't error and returns 0
 	mut a := []byte{len: 5}
-	nread := file_read.read_bytes_into(5, a) or {
+	nread := file_read.read_bytes_into(5, mut a) or {
 		eprintln(err)
 		int(-1)
 	}

vlib/sync/channel_polling_test.v

@@ -18,7 +18,7 @@ fn do_rec(ch chan int, resch chan i64, n int) {
 	mut sum := i64(0)
 	for _ in 0 .. n {
 		mut r := 0
-		for ch.try_pop(mut r) != .success {}
+		for ch.try_pop(r) != .success {}
 		sum += r
 	}
 	println(sum)
@@ -34,11 +34,11 @@ fn do_send(ch chan int, start, end int) {
 fn test_channel_polling() {
 	ch := chan int{cap: buflen}
 	resch := chan i64{}
-	for i in 0 .. nrec {
+	for _ in 0 .. nrec {
 		go do_rec(ch, resch, objs_per_thread)
 	}
 	mut n := nobj
-	for i in 0 .. nsend {
+	for _ in 0 .. nsend {
 		end := n
 		n -= objs_per_thread
 		go do_send(ch, n, end)