I reproduced the bug on a CentOS 5 server, with PHP 5.4 NTS loaded as mod_fcgid and opcache.so compiled with the currect GIT head sources. So this bug is not Windows specific!

The Superfish 7.x-1.9 can be found here:
https://drupal.org/project/superfish

Changed OS into 'Any'

The minimal script that triggers the problem:

<?php
function foo() {
	$speed = 'slow' || 'fast';
}
foo();
?>

It doesn't crash, but valgrind shows the source of the error

==12278== Invalid read of size 1
==12278==    at 0x4C1E335: accel_new_interned_string (zend_hash.h:282)
==12278==    by 0x4C252AD: zend_persist_zval_calc (zend_persist_calc.c:107)
==12278==    by 0x4C258F9: zend_persist_op_array_calc.part.2 (zend_persist_calc.c:148)
==12278==    by 0x4C250D2: zend_hash_persist_calc (zend_persist_calc.c:79)
==12278==    by 0x4C25971: zend_accel_script_persist_calc (zend_persist_calc.c:337)
==12278==    by 0x4C1F78B: compile_and_cache_file.constprop.19 (ZendAccelerator.c:1167)
==12278==    by 0x4C20291: persistent_compile_file (ZendAccelerator.c:1634)
==12278==    by 0x838B57C: zend_execute_scripts (zend.c:1308)
==12278==    by 0x832CAAA: php_execute_script (main.c:2506)
==12278==    by 0x8434E46: do_cli (php_cli.c:994)
==12278==    by 0x806F91C: main (php_cli.c:1378)
==12278==  Address 0x4d04c30 is 0 bytes inside a block of size 5 free'd
==12278==    at 0x4007B21: free (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==12278==    by 0x8381407: convert_to_boolean (zend_operators.c:543)
==12278==    by 0x4C2B252: zend_optimize_block (block_pass.c:1059)
==12278==    by 0x4C2F5EC: zend_optimizer (block_pass.c:2060)
==12278==    by 0x837F033: zend_llist_apply_with_argument (zend_llist.c:234)
==12278==    by 0x8380307: pass_two (zend_opcode.c:670)
==12278==    by 0x8373FEA: zend_do_end_function_declaration (zend_compile.c:1811)
==12278==    by 0x83550C5: zendparse (zend_language_parser.y:382)
==12278==    by 0x8356149: compile_file (zend_language_scanner.l:588)
==12278==    by 0x82347BC: phar_compile_file (phar.c:3383)
==12278==    by 0x4C1F5A4: compile_and_cache_file.constprop.19 (ZendAccelerator.c:1388)
==12278==    by 0x4C20291: persistent_compile_file (ZendAccelerator.c:1634)

It is quite incomprehensible for me, but I see some code like that in superfish.module and apparently you found out that that code triggers this issue.

Let me know when you have a patch and I will test it.

Solved by this patch:
https://github.com/zendtech/ZendOptimizerPlus/archive/master.zip

https://github.com/zendtech/ZendOptimizerPlus/archive/master.zip solves *nothing*
the same segfaults as https://bugs.php.net/bug.php?id=66460

the only solution currently is take the "opcache" folder from 5.5.6
and replace the one from 5.5.7/5.5.8, i tried the master above
a few minutes ago

[Wed Jan 15 22:57:48.019059 2014] [core:notice] [pid 28817] AH00052: child pid 28820 exit signal Segmentation fault (11)
[Wed Jan 15 22:57:49.020977 2014] [core:notice] [pid 28817] AH00052: child pid 28841 exit signal Segmentation fault (11)

@rhsoft: did you try the block_pass.c from the 5.5.6 tarball and the other files from the 5.5.8 tarball?

i took the source of https://github.com/zendtech/ZendOptimizerPlus/archive/master.zip and repalced the "opcache" folder of 5.5.8 tarball

thanks for disallow comments and close https://bugs.php.net/bug.php?id=66460
that will help to make things better...............

nothing is fixed - opcache with enabled optimizer which is 
default after 5.5.6 is broken and worked before
https://bugs.php.net/bug.php?id=66499

As the first comment says, this bug applies to PHP 5.4 as well as 5.5+. I just had to upgrade a site to 5.5 to fix it. I know 5.4 is in security-fix-only mode now, so I doubt this will ever get backported, but given that it was brought up during the Active Support period, I thought I'd mention it just in case.

PHP 5.4 does not have a bundled opcache. If you were using opcache with PHP 5.4 then the only way to get it is by using the ZendOptimizer sources from github. Those sources surely have the bugfix for this specific bug:
https://github.com/zendtech/ZendOptimizerPlus/blob/master/Optimizer/block_pass.c#L1060

You must have run into another bug.