[K/N] Parallelize marking in CMS GC

This change parallelizes marking by making each non-native Kotlin thread
mark its own view of the heap. To make this safe, we make flipping the
marking bit atomic which ensures that threads do not try to trace the
same objects.

Co-authored-by: Johan Bay <jobay@google.com>

Merge-request: KOTLIN-MR-423
Merged-by: Alexander Shabalin <alexander.shabalin@jetbrains.com>

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/BinaryOptions.kt

@@ -31,6 +31,8 @@ object BinaryOptions : BinaryOptionRegistry() {
 
     val gcSchedulerType by option<GCSchedulerType>()
 
+    val gcMarkSingleThreaded by booleanOption()
+
     val linkRuntime by option<RuntimeLinkageStrategyBinaryOption>()
 
     val bundleId by stringOption()

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanConfig.kt

@@ -170,6 +170,9 @@ class KonanConfig(val project: Project, val configuration: CompilerConfiguration
         configuration.get(BinaryOptions.gcSchedulerType) ?: defaultGCSchedulerType
     }
 
+    val gcMarkSingleThreaded: Boolean
+        get() = configuration.get(BinaryOptions.gcMarkSingleThreaded) == true
+
     val needVerifyIr: Boolean
         get() = configuration.get(KonanConfigKeys.VERIFY_IR) == true
 

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -2773,6 +2773,7 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
             return
 
         overrideRuntimeGlobal("Kotlin_destroyRuntimeMode", Int32(context.config.destroyRuntimeMode.value))
+        overrideRuntimeGlobal("Kotlin_gcMarkSingleThreaded", Int32(if (context.config.gcMarkSingleThreaded) 1 else 0))
         overrideRuntimeGlobal("Kotlin_workerExceptionHandling", Int32(context.config.workerExceptionHandling.value))
         overrideRuntimeGlobal("Kotlin_suspendFunctionsFromAnyThreadFromObjC", Int32(if (context.config.suspendFunctionsFromAnyThreadFromObjC) 1 else 0))
         val getSourceInfoFunctionName = when (context.config.sourceInfoType) {