Remove support for PHP5

PHP5 is no longer actively supported by the PHP developers and security
support for it ends completely at the end of 2018, so it doesn't make
sense to include support for it in the upcoming SWIG 4.0.0 release.

See #701.

Doc/Manual/Php.html

@@ -50,20 +50,13 @@
 
 
 <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
-OO wrappers for PHP5 was added in 1.3.30.  The PHP module now supports most
-of the features available in some of the other languages.
+In this chapter, we discuss SWIG's support of PHP.  SWIG currently supports
+generating wrappers for PHP7.  Support for PHP5 was removed in SWIG 4.0.0
+and support for PHP4 was removed in SWIG 1.3.37.
 </p>
 
 <p>
-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.
+Currently any PHP7 release should work.
 </p>
 
 <p>
@@ -81,9 +74,9 @@ available.
 
 
 <p>
-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>):
+To build a PHP extension, run swig using the <tt>-php7</tt> option as follows
+(<tt>-php</tt> is also supported and currently is an alias for <tt>-php7</tt>
+but prior to SWIG 4.0.0 it was an alias for <tt>-php5</tt>):
 </p>
 
 <div class="code"><pre>
@@ -107,9 +100,7 @@ also contain PHP class wrappers.
 SWIG can generate PHP extensions from C++ libraries as well when
 given the <tt>-c++</tt> option.  The support for C++ is discussed in
 more detail in <a href="#Php_nn2_6">section 27.2.6</a>.  The generated
-C++ wrapper will be called example_wrap.cpp (for PHP5) or
-example_wrap.cxx (for PHP7 where the default has been changed to align
-with SWIG's default for every other language).  You can specify a
+C++ wrapper will be called example_wrap.cxx.  You can specify a
 different extension for the C++ wrapper using <tt>-cppext</tt> -
 e.g. if you want example_wrap.cc use <tt>-cppext cc</tt>.
 </p>
@@ -172,8 +163,8 @@ PHP script which uses your extension:
 </pre></div>
 
 <p>
-But note that this doesn't work when running PHP through a webserver in PHP5.3
-and later - you'll need to use <tt>extension</tt> in <tt>php.ini</tt> as
+But note that <tt>dl()</tt> isn't supported when running PHP through a
+webserver - you'll need to use <tt>extension</tt> in <tt>php.ini</tt> as
 described above.
 </p>
 
@@ -199,7 +190,8 @@ It is important to understand that PHP uses a single global namespace
 into which all symbols from extension modules are loaded.  It is quite
 possible for names of symbols in one extension module to clash with
 other symbols unless care is taken to <tt>%rename</tt> them.  At present
-SWIG doesn't have support for the namespace feature added in PHP 5.3.
+SWIG doesn't have support for generating wrappers which make use of PHP's
+namespace feature.
 </p>
 
 <H3><a name="Php_nn2_1">35.2.1 Constants</a></H3>
@@ -525,13 +517,6 @@ this, one needs to include <b>phppointers.i</b> which defines the
 named typemap REF.
 </p>
 
-<p>
-Prior to SWIG 3.0, the REF typemaps relied on PHP's call-time
-pass-by-reference, which was deprecated in PHP 5.3 and removed in PHP 5.4.
-So if you use these REF typemaps, you should ensure that SWIG&ge;3.0 is
-used to generate wrappers from your interface file.
-</p>
-
 <p>
 In case you write your own typemaps, SWIG supports an attribute called
 <tt>byref</tt>: if you set that, then SWIG will make sure that the generated

Doc/Manual/Preprocessor.html

@@ -125,8 +125,7 @@ SWIGMZSCHEME                    Defined when using Mzscheme
 SWIGOCAML                       Defined when using Ocaml
 SWIGOCTAVE                      Defined when using Octave
 SWIGPERL                        Defined when using Perl
-SWIGPHP                         Defined when using PHP5 or PHP7
-SWIGPHP5                        Defined when using PHP5
+SWIGPHP                         Defined when using PHP (any version)
 SWIGPHP7                        Defined when using PHP7
 SWIGPIKE                        Defined when using Pike
 SWIGPYTHON                      Defined when using Python

Doc/Manual/SWIG.html

@@ -131,7 +131,6 @@ can be obtained by typing <tt>swig -help</tt> or <tt>swig
 -ocaml                Generate Ocaml wrappers
 -octave               Generate Octave wrappers
 -perl                 Generate Perl wrappers
--php5                 Generate PHP5 wrappers
 -php7                 Generate PHP7 wrappers
 -pike                 Generate Pike wrappers
 -python               Generate Python wrappers
@@ -145,7 +144,7 @@ can be obtained by typing <tt>swig -help</tt> or <tt>swig
 
 -c++                  Enable C++ processing
 -cppext <em>ext</em>           Change file extension of C++ generated files to <em>ext</em>
-                      (default is cxx, except for PHP5 which uses cpp)
+                      (default is cxx)
 -D<em>symbol</em>              Define a preprocessor symbol
 -Fmicrosoft           Display error/warning messages in Microsoft format
 -Fstandard            Display error/warning messages in commonly used format