[FIR] Resolve forks in constraint system after analysis of postponed lambda

When constraint system has forks in it usually we solve all of them before
  starting full completion of corresponding call. But if some call with
  forks was a last statement of postponed lambda, we will never call
  completion for it with FULL mode. Instead of it we complete it in PARTIAL
  mode and then just merge its constraint storage into storage of outer
  call. So all forks from this inner call just remain unresolved inside
  outer system without this fix

^KT-55966 Fixed

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -29848,6 +29848,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                 runTest("compiler/testData/diagnostics/tests/smartCasts/smartcastToNothingAfterCheckingForNull.kt");
             }
 
+            @Test
+            @TestMetadata("smartcastToStarProjection.kt")
+            public void testSmartcastToStarProjection() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/smartCasts/smartcastToStarProjection.kt");
+            }
+
             @Test
             @TestMetadata("thisWithLabel.kt")
             public void testThisWithLabel() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java

@@ -29944,6 +29944,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/tests/smartCasts/smartcastToNothingAfterCheckingForNull.kt");
             }
 
+            @Test
+            @TestMetadata("smartcastToStarProjection.kt")
+            public void testSmartcastToStarProjection() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/smartCasts/smartcastToStarProjection.kt");
+            }
+
             @Test
             @TestMetadata("thisWithLabel.kt")
             public void testThisWithLabel() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java

@@ -29848,6 +29848,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                 runTest("compiler/testData/diagnostics/tests/smartCasts/smartcastToNothingAfterCheckingForNull.kt");
             }
 
+            @Test
+            @TestMetadata("smartcastToStarProjection.kt")
+            public void testSmartcastToStarProjection() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/smartCasts/smartcastToStarProjection.kt");
+            }
+
             @Test
             @TestMetadata("thisWithLabel.kt")
             public void testThisWithLabel() throws Exception {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/PostponedArgumentsAnalyzer.kt

@@ -213,6 +213,7 @@ class PostponedArgumentsAnalyzer(
 
         lambda.analyzed = true
         lambda.returnStatements = returnArguments
+        c.resolveForkPointsConstraints()
 
         if (inferenceSession != null) {
             val postponedVariables = inferenceSession.inferPostponedVariables(lambda, builder, completionMode)

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

@@ -25,4 +25,5 @@ interface PostponedArgumentsAnalyzerContext : TypeSystemInferenceExtensionContex
     fun addOtherSystem(otherSystem: ConstraintStorage)
 
     fun getBuilder(): ConstraintSystemBuilder
+    fun resolveForkPointsConstraints()
 }

compiler/testData/diagnostics/tests/smartCasts/smartcastToStarProjection.fir.kt

@@ -0,0 +1,18 @@
+// SKIP_TXT
+// ISSUE: KT-55966
+// INFERENCE_HELPERS
+
+class Inv<T>
+
+abstract class A<T>
+
+fun <T> get(e: A<T>): T = null!!
+
+fun <K> produce(producer: () -> K): K = null!!
+
+fun <O> test(t: A<O>) {
+    @Suppress("UNCHECKED_CAST")
+    t as A<Inv<*>>
+    <!DEBUG_INFO_EXPRESSION_TYPE("Inv<*>")!>id(get(t))<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("Inv<*>")!>produce { get(t) }<!>
+}

compiler/testData/diagnostics/tests/smartCasts/smartcastToStarProjection.kt

@@ -0,0 +1,18 @@
+// SKIP_TXT
+// ISSUE: KT-55966
+// INFERENCE_HELPERS
+
+class Inv<T>
+
+abstract class A<T>
+
+fun <T> get(e: A<T>): T = null!!
+
+fun <K> produce(producer: () -> K): K = null!!
+
+fun <O> test(t: A<O>) {
+    @Suppress("UNCHECKED_CAST")
+    t as A<Inv<*>>
+    <!DEBUG_INFO_EXPRESSION_TYPE("Inv<*>")!>id(get(<!DEBUG_INFO_SMARTCAST!>t<!>))<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("Inv<*>")!>produce { get(<!DEBUG_INFO_SMARTCAST!>t<!>) }<!>
+}

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -29944,6 +29944,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/smartCasts/smartcastToNothingAfterCheckingForNull.kt");
             }
 
+            @Test
+            @TestMetadata("smartcastToStarProjection.kt")
+            public void testSmartcastToStarProjection() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/smartCasts/smartcastToStarProjection.kt");
+            }
+
             @Test
             @TestMetadata("thisWithLabel.kt")
             public void testThisWithLabel() throws Exception {