Description:
------------
If PHP builds with disabled opcache, then the HAVE_OPCACHE_FILE_CACHE macro
is undefined in the global php_config.h .

Compiling Opcache as an additional module with --enable-opcache-file 
in that case produces opcache.so with references to the zend_file_cache.h
functions from ZendAccelerator.c, but functions itself does not compiles
and links in the result opcache.so as HAVE_OPCACHE_FILE_CACHE is undef 
in the zend_file_cache.c .

(And compiling Opcache as an additional module with --disable-opcache-file 
goes fine, as HAVE_OPCACHE_FILE_CACHE is disable both in the global 
php_config.h and ZendAccelerator.c .)


Test script:
---------------
Compile PHP without Opcache (with --disable-opcache --disable-opcache-file)
and install it.
Then compile Opcache as a module:
cd ext/opcache
phpize
./configure --enable-opcache --enable-opcache-file
make
make install


Expected result:
----------------
php -r 'print "OK\n";'
OK


Actual result:
--------------
php -r 'print "OK\n";'
Failed loading opcache.so:  opcache.so: undefined symbol: zend_file_cache_script_load
OK