[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

Examples/php5/simple/Makefile

@@ -0,0 +1,20 @@
+TOP        = ../..
+SWIGEXE    = $(TOP)/../swig
+SWIG_LIB_DIR = $(TOP)/../$(TOP_BUILDDIR_TO_TOP_SRCDIR)Lib
+SRCS       = example.c
+TARGET     = example
+INTERFACE  = example.i
+LIBS       =
+SWIGOPT    =
+
+check: build
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' php_run
+
+build:
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' SRCS='$(SRCS)' \
+	SWIG_LIB_DIR='$(SWIG_LIB_DIR)' SWIGEXE='$(SWIGEXE)' \
+	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' \
+	php
+
+clean:
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' php_clean

Examples/php5/simple/example.c

@@ -0,0 +1,23 @@
+/* File : example.c */
+#include <stdio.h>
+
+/* A global variable */
+double Foo = 3.0;
+
+void print_Foo() {
+   printf("In C, Foo = %f\n",Foo);
+}
+
+/* Compute the greatest common divisor of positive integers */
+int gcd(int x, int y) {
+  int g;
+  g = y;
+  while (x > 0) {
+    g = x;
+    x = y % x;
+    y = g;
+  }
+  return g;
+}
+
+

Examples/php5/simple/example.i

@@ -0,0 +1,8 @@
+/* File : example.i */
+%module example
+
+%inline %{
+extern int    gcd(int x, int y);
+extern double Foo;
+void print_Foo();
+%}

Examples/php5/simple/runme.php

@@ -0,0 +1,25 @@
+<?php
+
+require "example.php";
+
+# Call our gcd() function
+
+$x = "42 aaa";
+$y = 105;
+$g = gcd($x,$y);
+print "The gcd of $x and $y is $g\n";
+
+# Manipulate the Foo global variable
+
+# Output its current value
+print "Foo = " . Foo_get() . "\n";
+
+# Change its value
+Foo_set(3.1415926);
+
+# See if the change took effect ( this isn't a good example for php, see
+#				  manual for why. )
+print "Foo = "  . Foo_get() . "\n";
+print_Foo();
+
+?>