FIR Completion: Add simple classifiers completion

- This also fixes a few test

idea/idea-completion/testData/basic/common/annotations/ParameterAnnotation2.kt

@@ -1,3 +1,4 @@
+// FIR_COMPARISON
 annotation class SHello
 
 fun foo(@S<caret>) { }

idea/idea-completion/testData/basic/common/lambdaSignature/ParameterType1.kt

@@ -1,3 +1,4 @@
+// FIR_COMPARISON
 fun bar() {
     val handler = { i: <caret> }
 }

idea/idea-completion/testData/basic/common/lambdaSignature/ParameterType2.kt

@@ -1,3 +1,4 @@
+// FIR_COMPARISON
 fun bar() {
     val handler = { i: Int, s: <caret> }
 }

idea/idea-completion/testData/basic/common/lambdaSignature/ParameterType3.kt

@@ -1,3 +1,4 @@
+// FIR_COMPARISON
 fun bar() {
     val handler = { i: List<<caret>> }
 }

idea/idea-completion/testData/basic/common/lambdaSignature/ParameterType4.kt

@@ -1,3 +1,4 @@
+// FIR_COMPARISON
 fun bar() {
     val handler = { i: Map<String, <caret> }
 }

idea/idea-completion/testData/basic/common/lambdaSignature/ParameterType5.kt

@@ -1,3 +1,4 @@
+// FIR_COMPARISON
 fun bar() {
     val handler = { i: Int, list: List<String>, s: <caret> }
 }

idea/idea-fir/src/org/jetbrains/kotlin/idea/completion/KotlinFirCompletionContributor.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.idea.frontend.api.InvalidWayOfUsingAnalysisSession
 import org.jetbrains.kotlin.idea.frontend.api.KtAnalysisSession
 import org.jetbrains.kotlin.idea.frontend.api.getAnalysisSessionFor
 import org.jetbrains.kotlin.idea.frontend.api.scopes.KtCompositeScope
+import org.jetbrains.kotlin.idea.frontend.api.scopes.KtScope
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtCallableSymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtSymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.KtNamedSymbol
@@ -21,10 +22,7 @@ import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.isExtension
 import org.jetbrains.kotlin.idea.frontend.api.types.KtType
 import org.jetbrains.kotlin.idea.references.mainReference
 import org.jetbrains.kotlin.lexer.KtTokens
-import org.jetbrains.kotlin.psi.KtExpression
+import org.jetbrains.kotlin.psi.*
-import org.jetbrains.kotlin.psi.KtFile
-import org.jetbrains.kotlin.psi.KtLabelReferenceExpression
-import org.jetbrains.kotlin.psi.KtSimpleNameExpression
 import org.jetbrains.kotlin.psi.psiUtil.getQualifiedExpressionForSelector
 
 class KotlinFirCompletionContributor : CompletionContributor() {
@@ -83,14 +81,19 @@ private object KotlinAvailableScopesCompletionProvider {
         with(getAnalysisSessionFor(originalFile).createContextDependentCopy()) {
             val (implicitScopes, implicitReceivers) = originalFile.getScopeContextForPosition(nameExpression)
 
-            if (explicitReceiver != null) {
+            when {
-                collectDotCompletion(result, implicitScopes, explicitReceiver)
+                nameExpression.parent is KtUserType -> collectTypesCompletion(result, implicitScopes)
-            } else {
+                explicitReceiver != null -> collectDotCompletion(result, implicitScopes, explicitReceiver)
-                collectDefaultCompletion(result, implicitScopes, implicitReceivers)
+                else -> collectDefaultCompletion(result, implicitScopes, implicitReceivers)
             }
         }
     }
 
+    private fun collectTypesCompletion(result: CompletionResultSet, implicitScopes: KtScope) {
+        val availableClasses = implicitScopes.getClassifierSymbols()
+        availableClasses.forEach { result.addSymbolToCompletion(it) }
+    }
+
     private fun KtAnalysisSession.collectDotCompletion(
         result: CompletionResultSet,
         implicitScopes: KtCompositeScope,
@@ -127,8 +130,7 @@ private object KotlinAvailableScopesCompletionProvider {
         availableNonExtensions.forEach { result.addSymbolToCompletion(it) }
         extensionsWhichCanBeCalled.forEach { result.addSymbolToCompletion(it) }
 
-        val availableClasses = implicitScopes.getClassifierSymbols()
+        collectTypesCompletion(result, implicitScopes)
-        availableClasses.forEach { result.addSymbolToCompletion(it) }
     }
 }