Reduce code smell - explicit (#83)

"explicit" should be used on single-parameter constructors and conversion operators

https://sonarcloud.io/organizations/pando-project/issues?resolved=false&rules=cpp%3AS1709

Signed-off-by: Bence Gabor Kis <kisbg@inf.u-szeged.hu>

src/runtime/NumberObject.cpp

@@ -76,7 +76,7 @@ inline void decomposeDouble(double number, bool& sign, int32_t& exponent, uint64
 // This is used in converting the integer part of a number to a string.
 class BigInteger {
 public:
-    BigInteger(double number)
+    explicit BigInteger(double number)
     {
         m_values.reserve(36);
         ASSERT(std::isfinite(number) && !std::signbit(number));