std: fix dependation cycle

std/jule/integrated/conv.jule

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD 3-Clause
 // license that can be found in the LICENSE file.
 
-use fastbytes for std::internal::fastbytes
 use utf16 for std::unicode::utf16
 
 // Builtin:
@@ -92,11 +91,12 @@ unsafe fn BytePtrToStr(s: *byte): str {
 // NULL terminated string pointer. If s contatins NULL termination at any location,
 // accepts NULL termination is the end of s and skips following bytes.
 fn StrToBytes(s: str): []byte {
-    mut i := fastbytes::FindByteStr(s, 0)
-    if i != -1 {
-        mut bytes := make([]byte, i+1)
-        copy(bytes, s[:len(bytes)])
-        ret bytes
+    for i, b in s {
+        if b == 0 {
+            mut bytes := make([]byte, i+1)
+            copy(bytes, s[:len(bytes)])
+            ret bytes
+        }
     }
     mut bytes := make([]byte, len(s)+1)
     copy(bytes, s)