Revisit unused global functions in jerry-core (#2450)

There are some leftover global functions in the code that are not
referenced at all anymore. These functions are removed by this
patch.

There are also some global functions that are only used in their
own modules. These functions are made static by this patch.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

jerry-core/ecma/base/ecma-helpers-number.c

@@ -351,7 +351,7 @@ ecma_number_is_infinity (ecma_number_t num) /**< ecma-number */
  *
  * @return shift of dot in the fraction
  */
-int32_t
+static int32_t
 ecma_number_get_fraction_and_exponent (ecma_number_t num, /**< ecma-number */
                                        uint64_t *out_fraction_p, /**< [out] fraction of the number */
                                        int32_t *out_exponent_p) /**< [out] exponent of the number */
@@ -410,7 +410,7 @@ ecma_number_get_fraction_and_exponent (ecma_number_t num, /**< ecma-number */
  *
  * @return ecma-number
  */
-ecma_number_t
+static ecma_number_t
 ecma_number_make_normal_positive_from_fraction_and_exponent (uint64_t fraction, /**< fraction */
                                                              int32_t exponent) /**< exponent */
 {