Detect debug when building

[Jurigag]

I have a small idea, sometimes i forgot to write builddev when i need to, how about:

• detect if we have php compiled as debug
• if yes then zephir build will always build extension with debug symbols(just zephir builddev)
• if not then as it is
• add zephir buildprod so someone can build extension without debug symbols anyway

[sjinks]

if (PHP_DEBUG) {
// ...
}

PHP_DEBUG constant is available since PHP 5.2.7

[sergeyklay]

Implemented in the 0.11.x branch