FIR: Add fast-path for getOrderedAllTypeVariables if no synthetics

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

@@ -391,7 +391,9 @@ class ConstraintSystemCompleter(private val components: BodyResolveComponents, p
             topLevel.collectAllTypeVariables()
         }
 
-        result.addAll(c.notFixedTypeVariables.filter { context.inferenceSession.isSyntheticTypeVariable(it.value.typeVariable) }.keys.asIterable())
+        if (context.inferenceSession.hasSyntheticTypeVariables()) {
+            result.addAll(c.notFixedTypeVariables.filter { context.inferenceSession.isSyntheticTypeVariable(it.value.typeVariable) }.keys.asIterable())
+        }
 
         require(result.size == c.notFixedTypeVariables.size) {
             val notFoundTypeVariables = c.notFixedTypeVariables.keys.toMutableSet().apply { removeAll(result) }

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

@@ -41,6 +41,8 @@ class FirBuilderInferenceSession(
     override val currentConstraintStorage: ConstraintStorage
         get() = ConstraintStorage.Empty
 
+    override fun hasSyntheticTypeVariables(): Boolean = false
+
     override fun isSyntheticTypeVariable(typeVariable: TypeVariableMarker): Boolean {
         return false
     }

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

@@ -144,6 +144,9 @@ class FirDelegatedPropertyInferenceSession(
         return typeContext.typeSubstitutorByTypeConstructor(bindings)
     }
 
+    override fun hasSyntheticTypeVariables(): Boolean {
+        return syntheticTypeVariableByTypeVariable.isNotEmpty()
+    }
 
     override fun isSyntheticTypeVariable(typeVariable: TypeVariableMarker): Boolean {
         return typeVariable in syntheticTypeVariableByTypeVariable.values

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

@@ -32,6 +32,7 @@ abstract class FirInferenceSession {
 
     abstract fun registerStubTypes(map: Map<TypeVariableMarker, StubTypeMarker>)
 
+    abstract fun hasSyntheticTypeVariables(): Boolean
     abstract fun isSyntheticTypeVariable(typeVariable: TypeVariableMarker): Boolean
     abstract fun fixSyntheticTypeVariableWithNotEnoughInformation(
         typeVariable: TypeVariableMarker,
@@ -66,6 +67,7 @@ abstract class FirStubInferenceSession : FirInferenceSession() {
 
     override fun registerStubTypes(map: Map<TypeVariableMarker, StubTypeMarker>) {}
 
+    override fun hasSyntheticTypeVariables(): Boolean = false
     override fun isSyntheticTypeVariable(typeVariable: TypeVariableMarker): Boolean = false
     override fun fixSyntheticTypeVariableWithNotEnoughInformation(
         typeVariable: TypeVariableMarker,