File _multibuild of Package gcc14

<multibuild>
<flavor>gcc14-testresults</flavor>
<flavor>cross-aarch64-gcc14-bootstrap</flavor>
<flavor>cross-aarch64-gcc14</flavor>
<flavor>cross-arm-gcc14</flavor>
<flavor>cross-avr-gcc14-bootstrap</flavor>
<flavor>cross-i386-gcc14</flavor>
</multibuild>