Replace compileOnly with testCompileOnly in :generators

In Gradle testCompileOnly configuration does not extend compileOnly.

Since :generators project does not have main source set,
compileOnly dependencies have never worked.

Instead "kotlin-reflect" was resolved transitevely trough
:compiler:frontend.script module (a runtime dependency becomes
a compile transitive dependency).

In ccd6263787 I replaced `runtime` dependency
on "kotlin-reflect" with `runtimeOnly` breaking `:generators:compileTestKotlin`.

generators/build.gradle.kts

@@ -16,8 +16,8 @@ dependencies {
     compile(projectTests(":kotlin-noarg-compiler-plugin"))
     compile(projectTests(":kotlin-sam-with-receiver-compiler-plugin"))
     compile(projectTests(":generators:test-generator"))
-    compileOnly(intellijDep("jps-build-test"))
-    compileOnly(project(":kotlin-reflect-api"))
+    testCompileOnly(intellijDep("jps-build-test"))
+    testCompileOnly(project(":kotlin-reflect-api"))
     testCompile(intellijDep("jps-build-test"))
     testRuntime(intellijDep()) { includeJars("idea_rt") }
     testRuntime(projectDist(":kotlin-reflect"))