In the ebuild line php-ext-base-r1_addtoinifiles "xdebug.profiler_output_name" '"crc32"' should be changed to: php-ext-base-r1_addtoinifiles "xdebug.profiler_output_name" '"cachegrind.out.%p"' because now that's the default config. Otherwise the output will be saved to /tmp/crc32 (this version interprets value of this config entry differently), which is most probably not what was intended.
Fixed for dev-php[45]/xdebug in CVS, thanks for reporting. Also added xdebug.trace_output_name="trace.%c".