translate_c: fix ternary operator output in C macros

[cmpute]

this is a fix for #24590 . Basically it tries to wrap all the conditions in ternary operation with a zero check.

[Vexu]

This version of translate-c is going to be deleted in favor of ziglang/translate-c: #24497. You should contribute this there instead.

[cmpute]

This version of translate-c is going to be deleted in favor of ziglang/translate-c: #24497. You should contribute this there instead.

Per this comment: #24546 (comment), maybe let's see if this can land in 0.15?

[ehaas]

Will this work if the check function returns a bool instead of int? I think full-featured support for the ternary operator in macros will require a helper function because any scalar type (ints, bools, floats, enums, pointers) can be used in the condition and the two result types are converted to a common type if necessary.

[cmpute]

Will this work if the check function returns a bool instead of int? I think full-featured support for the ternary operator in macros will require a helper function because any scalar type (ints, bools, floats, enums, pointers) can be used in the condition and the two result types are converted to a common type if necessary.

This doesn't support other scalar types yet. It's also necessary to improve the ternary operator translation in normal (non-macro) code, which currently also uses the macroIntToBool function.

[cmpute]

Any possibilities for this to be merged by the next minor version?