[PHP] Add support for PHP7.

PHP5's C extension API has changed substantially so you need to use
-php7 to specify you want PHP7 compatible wrappers.
Fixes https://github.com/swig/swig/issues/571

Doc/Manual/Php.html

@@ -49,19 +49,6 @@
 
 
 
-<p>
-SWIG supports generating wrappers for PHP5.  Support for PHP4 was removed
-in SWIG 1.3.37.  The PHP developers are no longer making new PHP4 releases,
-and won't even be patching critical security issues after 2008-08-08, so it
-doesn't make much sense for SWIG to continue to support PHP4 now.  If you
-really need to continue to use PHP4, just stick with SWIG 1.3.36.
-</p>
-
-<p>
-Currently any PHP5 release should work, but we don't regularly test with
-PHP &lt; 5.3.
-</p>
-
 <p>
 In this chapter, we discuss SWIG's support of PHP.  The PHP module
 was extensively rewritten in release 1.3.26, and support for generating
@@ -70,7 +57,17 @@ of the features available in some of the other languages.
 </p>
 
 <p>
-In order to use this module, you will need to have a copy of the PHP5
+SWIG supports generating wrappers for PHP5 and PHP7.  Support for PHP4 was removed
+in SWIG 1.3.37.
+</p>
+
+<p>
+Currently any PHP5 or PHP7 release should work, but we don't regularly test with
+PHP &lt; 5.3.
+</p>
+
+<p>
+In order to use this module, you will need to have a copy of the PHP
 include files to compile the SWIG generated files.  If you installed
 PHP from a binary package, you may need to install a "php-dev" or "php-devel"
 package for these to be installed.  You can find out where these files are
@@ -84,12 +81,13 @@ available.
 
 
 <p>
-To build a PHP extension, run swig using the <tt>-php</tt> option as
-follows:
+To build a PHP extension, run swig using the <tt>-php5</tt> or
+<tt>-php7</tt> option as follows (<tt>-php</tt> is also supported
+and currently is an alias for <tt>-php5</tt>):
 </p>
 
 <div class="code"><pre>
-swig -php example.i
+swig -php7 example.i
 </pre></div>
 
 <p>
@@ -102,7 +100,7 @@ The third file,
 <tt>example.php</tt> can be included by PHP scripts.  It attempts to
 dynamically load the extension and contains extra php code specified
 in the interface file.  If wrapping C++ code with PHP classes, it will
-also contain PHP5 class wrappers.
+also contain PHP class wrappers.
 </p>
 
 <p>
@@ -611,7 +609,7 @@ struct Complex {
 </pre></div>
 
 <p>
-Would be used in the following way from PHP5:
+Would be used in the following way from PHP:
 </p>
 
 <div class="code"><pre>
@@ -646,7 +644,7 @@ Member variables and methods are accessed using the <tt>-&gt;</tt> operator.
 <p>
 The <tt>-noproxy</tt> option flattens the object structure and
 generates collections of named functions (these are the functions
-which the PHP5 class wrappers call).  The above example results
+which the PHP class wrappers call).  The above example results
 in the following PHP functions:
 </p>
 

Doc/Manual/Preprocessor.html

@@ -125,7 +125,9 @@ SWIGMZSCHEME                    Defined when using Mzscheme
 SWIGOCAML                       Defined when using Ocaml
 SWIGOCTAVE                      Defined when using Octave
 SWIGPERL                        Defined when using Perl
-SWIGPHP                         Defined when using PHP
+SWIGPHP                         Defined when using PHP5 or PHP7
+SWIGPHP5                        Defined when using PHP5
+SWIGPHP7                        Defined when using PHP7
 SWIGPIKE                        Defined when using Pike
 SWIGPYTHON                      Defined when using Python
 SWIGR                           Defined when using R

Doc/Manual/SWIG.html

@@ -131,7 +131,8 @@ can be obtained by typing <tt>swig -help</tt> or <tt>swig
 -ocaml                Generate Ocaml wrappers
 -octave               Generate Octave wrappers
 -perl                 Generate Perl wrappers
--php                  Generate PHP wrappers
+-php5                 Generate PHP5 wrappers
+-php7                 Generate PHP7 wrappers
 -pike                 Generate Pike wrappers
 -python               Generate Python wrappers
 -r                    Generate R (aka GNU S) wrappers