Description:
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The documentation at php.net lists the PHP version in which a function was introduced, and when a function became deprecated.
It would be cool if an XML (or other format) would be included in the site which states only the functions and the version numbers. This would enable me to write a script to test a website for compliance.

My development server always runs the latest stable version of all software; I upgrade it once a week. However, customers' providers are not always as eager to upgrade. Having the XML described above would enable me to just develop the website as I see fit, then run a script to check all functions for compatibility, and then add some 'if (!function_exists())' alternatives where needed.

(Even cooler would be a function 'behave_as_version()' included in PHP itself, of course, but this would be considerably more work, I guess.)

Reproduce code:
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irrelevant

Expected result:
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<phpfunctions>
 <function>
  <name>array_diff</name>
  <introduced>4.0.1</name>
  <broken>4.0.4</broken>
 </function>
 <function>
  <name>array_map</name>
  <introduced>4.0.6</introduced>
 </function>
 <function>
  <name>trim</name>
  <introduced>3.x.x</introduced>
  <changelog>
   <change>
    <version>4.1.0</version>
    <description>The optional charlist parameter was added.</description>
   </change>
  </changelog>
 </function>
 <function>
  <name>some_function</name>
  <introduced>6.2.3</introduced>
  <deprecated>8.5.0</deprecated>
 </function>
</phpfunctions>

Actual result:
--------------
irrelevant