Refactor debugger tests

1. Move tests to their own module
2. Avoid sharing the 'tinyApp' project between tests
3. Clean up option directive handling

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/KotlinToJVMBytecodeCompiler.kt

@@ -398,7 +398,7 @@ object KotlinToJVMBytecodeCompiler {
             (File(path).takeIf(File::isAbsolute) ?: buildFile.resolveSibling(path)).absolutePath
         }
 
-    private class MainClassProvider(generationState: GenerationState, environment: KotlinCoreEnvironment) {
+    class MainClassProvider(generationState: GenerationState, environment: KotlinCoreEnvironment) {
         val mainClassFqName: FqName? by lazy { findMainClass(generationState, environment.getSourceFiles()) }
 
         private fun findMainClass(generationState: GenerationState, files: List<KtFile>): FqName? {

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/findMainClass.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2010-2019 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.cli.jvm.compiler
+
+import org.jetbrains.kotlin.codegen.state.GenerationState
+import org.jetbrains.kotlin.fileClasses.JvmFileClassUtil
+import org.jetbrains.kotlin.idea.MainFunctionDetector
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.psi.KtFile
+
+fun findMainClass(generationState: GenerationState, files: List<KtFile>): FqName? {
+    val mainFunctionDetector = MainFunctionDetector(generationState.bindingContext, generationState.languageVersionSettings)
+    return files.asSequence()
+        .map { file ->
+            if (mainFunctionDetector.hasMain(file.declarations))
+                JvmFileClassUtil.getFileClassInfoNoResolve(file).facadeClassFqName
+            else
+                null
+        }
+        .singleOrNull { it != null }
+}