[Platform API] Introduce fundamental abstraction of Platform

This is a large commit, which introduces general API for working with
abstraction of Platform.

- Add new abstraction to 'core' - SimplePlatform - which represents
exactly one platform
  - Clients are strongly prohibited to create instances of SimplePlatform
  by hand, instead, corresponding *Platforms abstraction should be used
  (e.g. JvmPlatforms, JsPlatforms, KonanPlatforms)

- Move TargetPlatform to 'core', it represents now a collection of
SimplePlatforms
  - Clients are strongly encouraged to use TargetPlatform
    (not SimplePlatform) in API, to enforce checks for multiplatform

- Provide a helper-extensions to work with TargetPlatform
(in particular, for getting a specific component platform)

- Remove MultiTargetPlatform in favour of TargetPlatform
  - Notably, this commit leaves another widely used duplicated abstraction,
    namely, IdePlatform. For the sake sanity, removal of IdePlatform is
    extracted in the separate commit.

idea/idea-native/src/org/jetbrains/kotlin/ide/konan/NativeIdePlatformKindTooling.kt

@@ -19,7 +19,7 @@ import org.jetbrains.kotlin.idea.platform.IdePlatformKindTooling
 import org.jetbrains.kotlin.platform.impl.NativeIdePlatformKind
 import org.jetbrains.kotlin.psi.KtFunction
 import org.jetbrains.kotlin.psi.KtNamedDeclaration
-import org.jetbrains.kotlin.resolve.TargetPlatform
+import org.jetbrains.kotlin.platform.TargetPlatform
 import javax.swing.Icon
 
 class NativeIdePlatformKindTooling : IdePlatformKindTooling() {

idea/idea-native/src/org/jetbrains/kotlin/ide/konan/NativePlatformKindResolution.kt

@@ -29,11 +29,10 @@ import org.jetbrains.kotlin.idea.compiler.IDELanguageSettingsProvider
 import org.jetbrains.kotlin.konan.file.File
 import org.jetbrains.kotlin.konan.library.*
 import org.jetbrains.kotlin.konan.util.KonanFactories
+import org.jetbrains.kotlin.platform.TargetPlatform
 import org.jetbrains.kotlin.platform.impl.NativeIdePlatformKind
-import org.jetbrains.kotlin.resolve.CompilerDeserializationConfiguration
-import org.jetbrains.kotlin.resolve.ImplicitIntegerCoercion
-import org.jetbrains.kotlin.resolve.TargetPlatform
-import org.jetbrains.kotlin.resolve.konan.platform.KonanPlatform
+import org.jetbrains.kotlin.platform.konan.KonanPlatforms
+import org.jetbrains.kotlin.resolve.*
 import org.jetbrains.kotlin.utils.addToStdlib.firstNotNullResult
 
 class NativePlatformKindResolution : IdePlatformKindResolution {
@@ -122,7 +121,7 @@ private fun createKotlinNativeBuiltIns(settings: PlatformAnalysisSettings, proje
 }
 
 // TODO: It depends on a random module's stdlib, propagate the actual module here.
-private fun findNativeStdlib(project: Project): NativeLibraryInfo? = getModuleInfosFromIdeaModel(project, KonanPlatform)
+private fun findNativeStdlib(project: Project): NativeLibraryInfo? = getModuleInfosFromIdeaModel(project, KonanPlatforms.defaultKonanPlatform)
     .firstNotNullResult { it.asNativeStdlib() }
 
 private fun IdeaModuleInfo.asNativeStdlib(): NativeLibraryInfo? = if ((this as? NativeLibraryInfo)?.isStdlib == true) this else null
@@ -149,7 +148,7 @@ class NativeLibraryInfo(project: Project, library: Library, root: File) : Librar
                 )
 
     override val platform: TargetPlatform
-        get() = KonanPlatform
+        get() = KonanPlatforms.defaultKonanPlatform
 
     override fun toString() = "Native" + super.toString()
 

idea/idea-native/src/org/jetbrains/kotlin/ide/konan/analyzer/NativeResolverForModuleFactory.kt

@@ -7,7 +7,6 @@ package org.jetbrains.kotlin.ide.konan.analyzer
 
 import org.jetbrains.kotlin.analyzer.*
 import org.jetbrains.kotlin.config.LanguageVersionSettings
-import org.jetbrains.kotlin.config.TargetPlatformVersion
 import org.jetbrains.kotlin.container.get
 import org.jetbrains.kotlin.context.ModuleContext
 import org.jetbrains.kotlin.descriptors.impl.CompositePackageFragmentProvider
@@ -15,10 +14,9 @@ import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.frontend.di.createContainerForLazyResolve
 import org.jetbrains.kotlin.ide.konan.NativeLibraryInfo
 import org.jetbrains.kotlin.ide.konan.createPackageFragmentProvider
+import org.jetbrains.kotlin.platform.konan.KonanPlatforms
 import org.jetbrains.kotlin.resolve.CodeAnalyzerInitializer
 import org.jetbrains.kotlin.resolve.TargetEnvironment
-import org.jetbrains.kotlin.resolve.TargetPlatform
-import org.jetbrains.kotlin.resolve.konan.platform.KonanPlatform
 import org.jetbrains.kotlin.resolve.konan.platform.NativePlatformCompilerServices
 import org.jetbrains.kotlin.resolve.lazy.ResolveSession
 import org.jetbrains.kotlin.resolve.lazy.declarations.DeclarationProviderFactoryService.Companion.createDeclarationProviderFactory
@@ -31,8 +29,7 @@ object NativeResolverForModuleFactory : ResolverForModuleFactory() {
         platformParameters: PlatformAnalysisParameters,
         targetEnvironment: TargetEnvironment,
         resolverForProject: ResolverForProject<M>,
-        languageVersionSettings: LanguageVersionSettings,
-        targetPlatformVersion: TargetPlatformVersion
+        languageVersionSettings: LanguageVersionSettings
     ): ResolverForModule {
 
         val declarationProviderFactory = createDeclarationProviderFactory(
@@ -47,8 +44,7 @@ object NativeResolverForModuleFactory : ResolverForModuleFactory() {
             moduleContext,
             declarationProviderFactory,
             CodeAnalyzerInitializer.getInstance(moduleContext.project).createTrace(),
-            KonanPlatform,
-            TargetPlatformVersion.NoVersion,
+            KonanPlatforms.defaultKonanPlatform,
             NativePlatformCompilerServices,
             targetEnvironment,
             languageVersionSettings