[NI] Update lambda result types.

When completing calls, update return types for functional descriptors
for lambdas using type inference results.

Add toString to some Call subclasses (for debugging purposes).

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/KotlinCallResolver.kt

@@ -102,7 +102,7 @@ class KotlinCallResolver(
         }
 
         return maximallySpecificCandidates.map {
-            kotlinCallCompleter.transformWhenAmbiguity(it)
+            kotlinCallCompleter.transformWhenAmbiguity(it, callContext.lambdaAnalyzer)
         }
     }
 }

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/ExternalComponents.kt

@@ -17,10 +17,8 @@
 package org.jetbrains.kotlin.resolve.calls.components
 
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
-import org.jetbrains.kotlin.resolve.calls.model.KotlinCall
-import org.jetbrains.kotlin.resolve.calls.model.KotlinCallArgument
-import org.jetbrains.kotlin.resolve.calls.model.KotlinResolutionCandidate
-import org.jetbrains.kotlin.resolve.calls.model.LambdaKotlinCallArgument
+import org.jetbrains.kotlin.resolve.calls.model.*
+import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.UnwrappedType
 
 interface IsDescriptorFromSourcePredicate: (CallableDescriptor) -> Boolean
@@ -39,4 +37,6 @@ interface LambdaAnalyzer {
     // todo this is hack for some client which try to read ResolvedCall from trace before all calls completed
     fun bindStubResolvedCallForCandidate(candidate: KotlinResolutionCandidate)
 
+    fun completeLambdaReturnType(lambdaArgument: ResolvedLambdaArgument, returnType: KotlinType)
+
 }

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/KotlinCallCompleter.kt

@@ -63,8 +63,8 @@ class KotlinCallCompleter(
         fun getBuilder(): ConstraintSystemBuilder
     }
 
-    fun transformWhenAmbiguity(candidate: KotlinResolutionCandidate): ResolvedKotlinCall =
-            toCompletedBaseResolvedCall(candidate.lastCall.constraintSystem.asCallCompleterContext(), candidate)
+    fun transformWhenAmbiguity(candidate: KotlinResolutionCandidate, lambdaAnalyzer: LambdaAnalyzer): ResolvedKotlinCall =
+            toCompletedBaseResolvedCall(candidate.lastCall.constraintSystem.asCallCompleterContext(), candidate, lambdaAnalyzer)
 
     fun completeCallIfNecessary(
             candidate: KotlinResolutionCandidate,
@@ -82,7 +82,7 @@ class KotlinCallCompleter(
             val c = candidate.lastCall.constraintSystem.asCallCompleterContext()
 
             topLevelCall.competeCall(c, lambdaAnalyzer)
-            return toCompletedBaseResolvedCall(c, candidate)
+            return toCompletedBaseResolvedCall(c, candidate, lambdaAnalyzer)
         }
 
         return ResolvedKotlinCall.OnlyResolvedKotlinCall(candidate)
@@ -90,13 +90,17 @@ class KotlinCallCompleter(
 
     private fun toCompletedBaseResolvedCall(
             c: Context,
-            candidate: KotlinResolutionCandidate
+            candidate: KotlinResolutionCandidate,
+            lambdaAnalyzer: LambdaAnalyzer
     ): ResolvedKotlinCall.CompletedResolvedKotlinCall {
         val currentSubstitutor = c.buildResultingSubstitutor()
         val completedCall = candidate.toCompletedCall(currentSubstitutor)
         val competedCalls = c.innerCalls.map {
             it.candidate.toCompletedCall(currentSubstitutor)
         }
+        c.lambdaArguments.forEach {
+            lambdaAnalyzer.completeLambdaReturnType(it, currentSubstitutor.safeSubstitute(it.returnType))
+        }
         return ResolvedKotlinCall.CompletedResolvedKotlinCall(completedCall, competedCalls)
     }