When we dont check for request size we need to take care that the lef…

…t shift does not panic

fuzz/fuzz_targets/decode.rs

@@ -4,7 +4,7 @@ extern crate ruzstd;
 use ruzstd::frame_decoder;
 
 fuzz_target!(|data: &[u8]| {
-    let mut content = data.clone();
+    let mut content = data;
     let mut frame_dec = frame_decoder::FrameDecoder::new();
 
     match frame_dec.reset(&mut content){

src/decoding/bit_reader_reverse.rs

@@ -127,7 +127,7 @@ impl<'s> BitReaderReversed<'s> {
             let emulated_read_shift = signed_n - self.bits_remaining();
             let v = self.get_bits(self.bits_remaining() as u8);
             debug_assert!(self.idx == 0);
-            let value = v << emulated_read_shift;
+            let value = v.wrapping_shl(emulated_read_shift as u32);
             self.idx -= emulated_read_shift;
             return value;
         }