PHP 7.0.31, 7.1.20和7.2.8正式发布，多项内容修复

PHP 7.0.31, 7.1.20, 7.2.8 正式发布了。PHP（PHP：Hypertext Preprocessor）是一种在电脑上执行的脚本语言，主要是用途在于处理动态网页，也包含了命令列执行接口（command line interface），或者产生图形使用者接口（GUI）程式。

版本主要还是修复 bug，改进日志如下：

PHP 7.0.31
  
  - Exif:
    . Fixed bug #76423 (Int Overflow lead to Heap OverFlow in
      exif_thumbnail_extract of exif.c). (Stas)
    . Fixed bug #76557 (heap-buffer-overflow (READ of size 48) while reading exif
      data). (Stas)
  
  - Win32:
    . Fixed bug #76459 (windows linkinfo lacks openbasedir check). (Anatol)
  

PHP 7.1.20
  
  - Core:
    . Fixed bug #76534 (PHP hangs on 'illegal string offset on string references
      with an error handler). (Laruence)
    . Fixed bug #76502 (Chain of mixed exceptions and errors does not serialize
      properly). (Nikita)
  
  - Date:
    . Fixed bug #76462 (Undefined property: DateInterval::$f). (Anatol)
  
  - FPM:
    . Fixed bug #73342 (Vulnerability in php-fpm by changing stdin to
      non-blocking). (Nikita)
  
  - GMP:
    . Fixed bug #74670 (Integer Underflow when unserializing GMP and possible
      other classes). (Nikita)
  
  - intl:
    . Fixed bug #76556 (get_debug_info handler for BreakIterator shows wrong
      type). (cmb)
  
  - mbstring:
    . Fixed bug #76532 (Integer overflow and excessive memory usage
      in mb_strimwidth). (MarcusSchwarz)
  
  - PGSQL:
    . Fixed bug #76548 (pg_fetch_result did not fetch the next row). (Anatol)
  
  - phpdbg:
    . Fix arginfo wrt. optional/required parameters. (cmb)
  
  - Reflection:
    . Fixed bug #76536 (PHP crashes with core dump when throwing exception in
      error handler). (Laruence)
    . Fixed bug #75231 (ReflectionProperty#getValue() incorrectly works with
      inherited classes). (Nikita)
  
  - Standard:
    . Fixed bug #76505 (array_merge_recursive() is duplicating sub-array keys).
      (Laruence)
    . Fixed bug #71848 (getimagesize with $imageinfo returns false). (cmb)