Update Git build requirements

Cf. <php/php-src#6516>.


git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@352238 c90b9560-bf6c-de11-be94-00142212c4b1

Author: cmb69

install/unix/index.xml

@@ -61,7 +61,7 @@
     <itemizedlist>
      <listitem>
       <simpara>
-       autoconf: 2.13+ (for PHP &lt; 5.4.0), 2.59+ (for PHP &gt;= 5.4.0), 2.64+ (for PHP &gt;= 7.2.0)
+       autoconf: 2.59+ (for PHP &gt;= 7.0.0), 2.64+ (for PHP &gt;= 7.2.0)
       </simpara>
      </listitem>
      <listitem>
@@ -76,36 +76,14 @@
      </listitem>
      <listitem>
       <simpara>
-       re2c: Version 0.13.4 or newer
-      </simpara>
-     </listitem>
-     <listitem>
-      <simpara>
-       flex: Version 2.5.4 (for PHP &lt;= 5.2)
+       re2c: 0.13.4+ (for PHP &gt; 7.0.0), 0.13.7+ (for PHP &gt; 8.0.0)
       </simpara>
      </listitem>
      <listitem>
       <simpara>
        bison:
       </simpara>
       <itemizedlist>
-       <listitem>
-        <simpara>
-         PHP 5.4: 1.28, 1.35, 1.75, 1.875, 2.0, 2.1, 2.2, 2.3, 2.4, 2.4.1,
-         2.4.2, 2.4.3, 2.5, 2.5.1, 2.6, 2.6.1, 2.6.2, 2.6.4
-        </simpara>
-       </listitem>
-       <listitem>
-        <simpara>
-         PHP 5.5: 2.4, 2.4.1, 2.4.2, 2.4.3, 2.5, 2.5.1, 2.6, 2.6.1, 2.6.2,
-         2.6.3, 2.6.4, 2.6.5, 2.7
-        </simpara>
-       </listitem>
-       <listitem>
-        <simpara>
-         PHP 5.6: &gt;= 2.4, &lt; 3.0
-        </simpara>
-       </listitem>
        <listitem>
         <simpara>
          PHP 7.0 - 7.3: 2.4 or later (including Bison 3.x)