Fixed: Potential out of bounds read in SIMD scanners

The previous code did not correctly account for the initial match of the first byte of the pattern moving the match pointer of up to ('RegisterLength' - 1). This code accounts for this with `(patternVectors.Length + 1) * (RegisterLength)`

Reloaded.Memory.Sigscan/Scanner_AVX2.cs

@@ -55,7 +55,7 @@ public static PatternScanResult FindPatternAvx2(byte* data, int dataLength, stri
         int matchTableLength = matchTable.Length;
 
         var firstByteVec     = Vector256.Create(patternData.Bytes[patternData.LeadingIgnoreCount]);
-        int searchLength = dataLength - (patternData.Bytes.Length +  AvxRegisterLength);
+        int searchLength = dataLength - ((patternVectors.Length + 1) * (AvxRegisterLength));
 
         int leadingIgnoreCount = patternData.LeadingIgnoreCount;
         ref var pVec = ref patternVectors[0];
@@ -68,11 +68,8 @@ public static PatternScanResult FindPatternAvx2(byte* data, int dataLength, stri
         var dataMaxPtr = dataPtr + searchLength;
         for (; dataPtr < dataMaxPtr; dataPtr++)
         {
-            if (dataPtr > (void*)0x00000001778b1000)
-            {
-                var a = 5;
-            }
-
+            var lastDataPtr = dataPtr;
+
             // Problem: If pattern starts with unknown, will never match.
             var rhs = Avx.LoadVector256(dataPtr);
             var equal = Avx2.CompareEqual(pFirstByteVec, rhs);

Reloaded.Memory.Sigscan/Scanner_SSE2.cs

@@ -54,7 +54,7 @@ public static PatternScanResult FindPatternSse2(byte* data, int dataLength, stri
         int matchTableLength = matchTable.Length;
 
         var firstByteVec  = Vector128.Create(patternData.Bytes[patternData.LeadingIgnoreCount]);
-        int searchLength = dataLength - (patternData.Bytes.Length +  SseRegisterLength);
+        int searchLength = dataLength - ((patternVectors.Length + 1) * (SseRegisterLength));
 
         int leadingIgnoreCount = patternData.LeadingIgnoreCount;
         ref var pVec = ref patternVectors[0];