In the compiler, 'FirLazyDeclarationResolver' assumes
'lazyResolveToPhase()' appear only during code analysis. So there is
a check that requires calls to be wrapped with 'startResolvingPhase()'
and 'finishResolvingPhase()'. Checkers and backend are run on fully
analyzed code, so there is no need in calling 'lazyResolveToPhase()'
in the first place.
In the IDE, however, it's impossible to analyze all code in a project
before running the backend. Generally, it's not a problem as files that
are explicitly passed to the backend go through all FIR phases.
'IrBuiltInsOverFir', though, perform symbol lookups, so unresolved-yet
declarations might appear.
Yan Zhulanow
6c6cf9977b