Build: remove obsolete compiler arguments

These compiler arguments enable features which are enabled by default in
the current Kotlin anyway.

The only exception is in :compiler:cli which uses an old language
version.

compiler/tests-common/build.gradle.kts

@@ -74,12 +74,6 @@ dependencies {
     testApiJUnit5()
 }
 
-tasks.withType<org.jetbrains.kotlin.gradle.dsl.KotlinCompile<*>> {
-    kotlinOptions {
-        freeCompilerArgs += "-Xinline-classes"
-    }
-}
-
 sourceSets {
     "main" { }
     "test" { projectDefault() }