don't create lookup elements for invalid PSI (EA-49434)
don't display quick doc for invalid lookup element (EA-51188)
consider call & chain elements invalid when substitutor is invalid (EA-47282 - PIEAE: PsiUtilCore.ensureValid)
catch invalid lookup elements early
test: FS refresh on Unicode paths
Cleanup (extra spaces)
new inference: fair reject Object
new inference: accept methods in lambda return statements as standalone when they do not depend on lambda params
new inference: use type arguments during reduction
new inference: extract B1 step
new inference: proper type subtyping
new inference: infer till B1
testdata