Fix TypeUtils.makeNullableAsSpecified for SimpleTypeWithEnhancement and
FlexibleTypeWithEnhancement: change nullability of enhancement too. This
fixes several false-positive warnings, like in KT-20855 and KT-20466.
Note that it removes warning in some cases (see testdata change for
uselessElvisRightIsNull.kt). However, this removes warning about
*unnecessary* elvis, i.e. this fixed introduces weak false-negatives, which
is acceptable for the moment.
#KT-20855 Fixed Target versions 1.2.30
#KT-20466 Fixed Target versions 1.2.30
#KT-21238 Fixed Target versions 1.2.30
This NPE was introduced in ce41b5745a
Prior to the latter change there was a synthetic PSI element for each
equals-related call, thus callOperationNode was not null here.
== are intentionally treated as safe calls, but for nullability checker
it's not relevant, it only should report warnings on real safe-calls
Before this chanhe, these annotations are simply ignored, but they should
preserve flexibility in case of enhanced nullability obtained from
enclosing default qualifier
#KT-20158 Fixed
Mikhael Bogdanov