FIR IDE: replace javax threadsafe annotations with custom ones

javax.annotation.concurrent may not be present for some JDKs

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/FirIdeModuleLibraryDependenciesSymbolProvider.kt

@@ -14,7 +14,7 @@ import org.jetbrains.kotlin.fir.resolve.providers.impl.FirDependenciesSymbolProv
 import org.jetbrains.kotlin.idea.caches.project.IdeaModuleInfo
 import org.jetbrains.kotlin.idea.caches.project.isLibraryClasses
 import org.jetbrains.kotlin.idea.caches.resolve.IDEPackagePartProvider
-import javax.annotation.concurrent.NotThreadSafe
+import org.jetbrains.kotlin.idea.fir.low.level.api.annotations.NotThreadSafe
 
 
 @NotThreadSafe

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/FirIdeSessionProvider.kt

@@ -12,7 +12,7 @@ import org.jetbrains.kotlin.fir.java.FirProjectSessionProvider
 import org.jetbrains.kotlin.idea.caches.project.getModuleInfo
 import org.jetbrains.kotlin.psi.KtElement
 import java.util.concurrent.ConcurrentHashMap
-import javax.annotation.concurrent.ThreadSafe
+import org.jetbrains.kotlin.idea.fir.low.level.api.annotations.ThreadSafe
 
 @ThreadSafe
 internal class FirIdeSessionProvider(project: Project) : FirProjectSessionProvider(project) {

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/annotations/threads.kt

@@ -0,0 +1,12 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.fir.low.level.api.annotations
+
+@Target(AnnotationTarget.CLASS)
+annotation class ThreadSafe
+
+@Target(AnnotationTarget.CLASS)
+annotation class NotThreadSafe

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/element/builder/FirElementBuilder.kt

@@ -20,7 +20,7 @@ import org.jetbrains.kotlin.idea.fir.low.level.api.util.FirElementFinder
 import org.jetbrains.kotlin.idea.util.getElementTextInContext
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.containingClassOrObject
-import javax.annotation.concurrent.ThreadSafe
+import org.jetbrains.kotlin.idea.fir.low.level.api.annotations.ThreadSafe
 
 /**
  * Maps [KtElement] to [FirElement]

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/file/builder/FirFileBuilder.kt

@@ -13,7 +13,7 @@ import org.jetbrains.kotlin.fir.resolve.transformers.createTransformerBasedProce
 import org.jetbrains.kotlin.fir.scopes.FirScopeProvider
 import org.jetbrains.kotlin.idea.fir.low.level.api.FirIdeSessionProvider
 import org.jetbrains.kotlin.psi.KtFile
-import javax.annotation.concurrent.ThreadSafe
+import org.jetbrains.kotlin.idea.fir.low.level.api.annotations.ThreadSafe
 
 /**
  * Responsible for building [FirFile] by [KtFile]

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/file/builder/ModuleFileCache.kt

@@ -16,7 +16,7 @@ import java.util.*
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.locks.ReentrantLock
 import java.util.concurrent.locks.ReentrantReadWriteLock
-import javax.annotation.concurrent.ThreadSafe
+import org.jetbrains.kotlin.idea.fir.low.level.api.annotations.ThreadSafe
 import kotlin.concurrent.withLock
 
 /**