iccDEV: UB in CIccOpDefEnvVar::Exec()

iccDEV provides a set of libraries and tools for working with ICC color management profiles. Prior to version 2.3.1.6, a crafted ICC profile can trigger Undefined Behavior (UB) in CIccOpDefEnvVar::Exec() due to invalid enum values being loaded for icSigCmmEnvVar. The issue is observable under UBSan as a “load of value … not a valid value for type icSigCmmEnvVar”, indicating an invalid enum/type value being consumed during ICC profile processing. This issue has been patched in version 2.3.1.6.