tests: Support custom konan.home for platform lib tests

* Move testLibrary tasks from klib into backend.native/tests
 * Support konan.home property in them

klib/build.gradle

@@ -23,33 +23,4 @@ apply plugin: 'kotlin'
 dependencies {
     compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
     compile project(path: ':backend.native', configuration: 'cli_bc')
-}
-
-def dist = distDir.absolutePath
-def suffix = isWindows() ? ".bat" : ""
-
-// TODO: Ideally we want to write just konanArtifacts{} clause here,
-// but we need to make Kotlin/Native Gradle Plugin a dependence
-// of our buildScripts first.
-task compileKonanTestLibrary(type: Exec) {
-    dependsOn ':dist'
-
-    def compiler = "$dist/bin/konanc$suffix"
-    def source = 'src/testLibrary'
-    def artifact = 'build/konan/bin/testLibrary'
-
-    executable compiler
-    args source, '-o', artifact, '-p', 'library'
-}
-
-task installTestLibrary(type: Exec) {
-    dependsOn 'compileKonanTestLibrary'
-
-    def tool = "$dist/bin/klib$suffix"
-    def repo = "$dist/klib/common"
-    def library = 'build/konan/bin/testLibrary.klib'
-
-    executable tool
-    args 'install', library, '-repository', repo
-}
-
+}

klib/src/testLibrary/kotlin/test_platform_lib.kt

@@ -1,9 +0,0 @@
-package test.konan.platform
-
-fun produceMessage() {
-    println("""This is a side effect of a test library linked into the binary.
-You should not be seeing this.
-""")
-}
-
-val x: Unit = produceMessage()