Add a switch to destroy runtime only on shutdown (#4482)

kotlin-native/build-tools/src/main/kotlin/org/jetbrains/kotlin/KotlinNativeTest.kt

@@ -419,8 +419,12 @@ open class KonanDynamicTest : KonanStandaloneTest() {
     @Input
     lateinit var cSource: String
 
+    @Input
     var clangTool = "clang"
 
+    @Input
+    var clangFlags: List<String> = listOf()
+
     // Replace testlib_api.h and all occurrences of the testlib with the actual name of the test
     private fun processCSource(): String {
         val sourceFile = File(cSource)
@@ -453,7 +457,7 @@ open class KonanDynamicTest : KonanStandaloneTest() {
                     "-c",
                     "-o", "$executable.o",
                     "-I", artifactsDir
-            )
+            ) + clangFlags
             it.standardOutput = log
             it.errorOutput = log
             it.isIgnoreExitValue = true
@@ -485,4 +489,4 @@ open class KonanDynamicTest : KonanStandaloneTest() {
             it.execute()
         }
     }
-}
+}