Description:
------------
http://news.php.net/php.internals/55662

I'm writing a C++ extension to PHP.
When declaring a INI entry I get the following warning, multiple times:
warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

This only arises when compiling with a C++ compiler.
The right and easy fix seems to set some fields to const char *.
Some may even be set to const char * const (but this alternative seems
to be used
nowhere).

The proposed patch is against the php5-dev-5.3.8-2 package of debian sid:
PHP 5.3.8-2 with Suhosin-Patch (cli) (built: Sep 12 2011 07:28:26)

Test script:
---------------
Write a C++ extension:
config.m4 should contain PHP_REQUIRE_CXX().

Declare your module:
zend_module_entry quezako_module_entry = {
   STANDARD_MODULE_HEADER,
   "YourExtensionName", // (1 warning here)
   [...],
   "0.42", // (1 warning here)
   [...],
   STANDARD_MODULE_PROPERTIES_EX
};

Declare an INI entry:
PHP_INI_BEGIN()
STD_PHP_INI_ENTRY(
   "extensionName.variable", // (1 warning here)
   "default value", // (1 warning here)
   [...]
)
PHP_INI_END()

Expected result:
----------------
No compilation warning.

Actual result:
--------------
Multiple of the following warning:
warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

Using the very common fix of prepending (char*) to the string constant is
especially harmful here, because of ZEND_INI_ENTRY3_EX using sizeof() on in: it
returns 4/8 (32/64bits platform).
Using a cast to char[] solves the problem, but the above fix is a very very
common mistake.

If the target fields were const char*, no compilation warning would be rose.