Add test on object with tests in common module

^KT-35480 In Progress

(current behavior is undesired, see fix in next commit)

idea/idea-gradle/tests/org/jetbrains/kotlin/idea/codeInsight/gradle/GradleTestRunConfigurationAndHighlightingTest.kt

@@ -31,6 +31,11 @@ class GradleTestRunConfigurationAndHighlightingTest : GradleImportingTestCase()
         doTest()
     }
 
+    @Test
+    fun multiplatformTestsInObject() {
+        doTest()
+    }
+
     private fun doTest() {
         val files = importProjectFromTestData()
         val project = myTestFixture.project

idea/testData/gradle/testRunConfigurations/multiplatformTestsInObject/build.gradle

@@ -0,0 +1,53 @@
+plugins {
+    id 'org.jetbrains.kotlin.multiplatform' version '1.3.61'
+}
+repositories {
+    mavenCentral()
+}
+group 'com.example'
+version '0.0.1'
+
+kotlin {
+    jvm()
+    js {
+        browser {
+        }
+        nodejs {
+        }
+    }
+
+    sourceSets {
+        commonMain {
+            dependencies {
+                implementation kotlin('stdlib-common')
+            }
+        }
+        commonTest {
+            dependencies {
+                implementation kotlin('test-common')
+                implementation kotlin('test-annotations-common')
+            }
+        }
+        jvmMain {
+            dependencies {
+                implementation kotlin('stdlib-jdk8')
+            }
+        }
+        jvmTest {
+            dependencies {
+                implementation kotlin('test')
+                implementation kotlin('test-junit')
+            }
+        }
+        jsMain {
+            dependencies {
+                implementation kotlin('stdlib-js')
+            }
+        }
+        jsTest {
+            dependencies {
+                implementation kotlin('test-js')
+            }
+        }
+    }
+}

idea/testData/gradle/testRunConfigurations/multiplatformTestsInObject/src/commonTest/kotlin/sample/SampleTests.kt

@@ -0,0 +1,9 @@
+package sample
+
+import kotlin.test.Test
+import kotlin.test.assertTrue
+
+object <lineMarker descr="Run Test" settings="Nothing here">Obj</lineMarker> {
+    @Test
+    fun <lineMarker descr="Run Test" settings=" cleanJsBrowserTest jsBrowserTest --tests \"sample.Obj.myTest\" cleanJsNodeTest jsNodeTest --tests \"sample.Obj.myTest\" cleanJvmTest jvmTest --tests \"sample.Obj.myTest\" --continue">myTest</lineMarker>() {}
+}