A crash report came into security@ (which needn't have been private)
about a segfault in response to trying to compile clearly broken code.
https://github.com/php/php-src/pull/2395 is a fix for this, but before
I merge it (and check how far back it goes -- my suspicion is 7.0),
I'm hoping for some feedback about the approach.
In short: It reduces the footprint for declare values from "any
expression" to "number and string literals". This technically could
break existing code since right now something like
declare(ticks=array()) is technically valid... even if terrible.
An alternate fix (and perhaps something to do in addition to this fix)
would be to add a check in zend_compile.c to verify that the value
type is ZEND_AST_ZVAL.
-Sara