Move isolated addSuppressed extension test to jvm tests

Conditions for being isolated do not hold anymore:
it tested that addSuppressed extension could work without kotlin-stdlib-jdk7,
but now the latter is merged to kotlin-stdlib and thus always present

#KT-51907

libraries/stdlib/jdk7/build.gradle

@@ -17,11 +17,6 @@ sourceSets {
         kotlin {
         }
     }
-    noJdk7Test {
-        kotlin {
-            srcDir 'testNoJdk7'
-        }
-    }
     java9 {
         java {
             srcDir 'java9'
@@ -29,10 +24,6 @@ sourceSets {
     }
 }
 
-configurations {
-    noJdk7TestApi.extendsFrom(testApi)
-}
-
 dependencies {
     api project(':kotlin-stdlib')
     testApi project(':kotlin-test:kotlin-test-junit')
@@ -88,12 +79,4 @@ configureFrontendIr(project)
 
 LibrariesCommon.configureJava9Compilation(project, 'kotlin.stdlib.jdk7')
 
-task testNoJdk7(type: Test, dependsOn: noJdk7TestClasses) {
-    group = "verification"
-
-    testClassesDirs = sourceSets.noJdk7Test.output.classesDirs
-    classpath = sourceSets.noJdk7Test.runtimeClasspath
-}
-
-check.dependsOn testNoJdk7