Log Message:
Update to 3.46

Upstream changes:
 3.46 - 2019-04-20

    * Fix the isFOO character type classification macros to work properly on
       all versions, as follows:
         * Fixed isALNUM, isALPHA, isDIGIT, isIDFIRST, isLOWER, and isUPPER on
           very early perls to not be locale-dependent
         * Fixed isASCII on early perls to work with signed char arguments
         * Fixed isCNTRL on early perls to know that DEL is a control
         * Fixed isSPACE on perls before 5.20 to know that VERTICAL TAB is a
           space
         * Added isALPHANUMERIC, synonym for isALNUMC
         * Added isIDCONT, to match legal non-initial characters in an
           identifier
         * Added isOCTAL, to match [0-7]
         * Added isWORDCHAR, synonym for isALNUM
         * Make all the character classification isFOO macros work on EBCDIC
           platforms on all versions
         * Added isFOO_A synonyms for all character classification isFOO
           macros
   * Provide LIKELY/UNLIKELY branch prediction
   * Provide av_tindex/av_top_index
   * Provide __ASSERT_ for assertions inside macros
   * Provide UTF8_SAFE_SKIP
   * Provide my_strnlen()
   * Provide utf8_to_uvchr_buf()
   * Replace utf8_to_uvchr() with a safer version
   * Provide UNICODE_REPLACEMENT