Fixing code generation for Result<bool> in Kotlin

[emarteca]

The general case for dealing with Result in Kotlin doesn't work for booleans.
Previously, generating the Kotlin code for a Rust function that returned a Result<bool> would be as follows:

Rust

pub fn test() -> Result<bool, ()> {
    todo!()            
}

Generated Kotlin (with the bug specified in a comment):

    fun test(): Res<Boolean, Unit> {
          val returnVal = lib.Why_test();
          if (returnVal.isOk == 1.toByte()) {
              return returnVal.union.ok.ok() > 0 // THIS IS A BUG THIS IS INVALID
          } else {
              return Err(Unit)
          }
      }

For booleans, this error line should instead be return (returnVal.union.ok > 0).ok() . This CL fixes this problem.

[emarteca]

@jcrist1

[emarteca]

oh hang on, the same bug shows up for some other primitive types too. let me fix them all in this PR