Description:
------------
The attached patch Introduces support for GCC alloc_size attribute, very useful 
to catch buffer overflows at compile time.





Test script:
---------------
PHP_FUNCTION(verybuggy) {
[...]

char *p;
p = emalloc(6);
strcpy(p,"cdcdccdscdscscsdcscddsc");
[...]
}

Expected result:
----------------
#make

buggy.c:N:N:
/usr/include/bits/string3.h:107:3: warning: call to __builtin___strcpy_chk will 
always overflow destination buffer


Actual result:
--------------
No warning at all, dangerous code goes unnoticed.