Optimizer assumes enum variable can only have value of enumeration constants

https://e2e.ti.com/support/development_tools/compiler/int-compiler/f/85/t/473218

Don't make enumerated types with constants only for 0 and 1 if other values may be used. Either add a third value, or use values different than 0 and 1, or avoid using values that aren't the enumeration constants.