Fix invalid iterator increment

Author: hrydgard

Core/SaveState.cpp

@@ -281,7 +281,11 @@ namespace SaveState
 						if (blockSize > 0) {
 							result.insert(result.end(), compressed.begin() + i, compressed.begin() + i + blockSize);
 							i += blockSize;
-							basePos += blockSize;
+							// This check is to avoid advancing basePos out of range, which MSVC catches.
+							// When this happens, we're at the end of decoding anyway.
+							if (base.end() - basePos >= blockSize) {
+								basePos += blockSize;
+							}
 						}
 					}
 				}