[K/N] Disable debug info in runtime by default

Bundle grows 200mb if debug info is enabled, it's too much.
But probably, this can be useful for debug, so we need gradle option.

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

@@ -16,6 +16,8 @@ import org.jetbrains.kotlin.konan.target.KonanTarget
 import org.jetbrains.kotlin.konan.target.SanitizerKind
 import java.io.File
 import javax.inject.Inject
+import kotlinBuildProperties
+import isNativeRuntimeDebugInfoEnabled
 
 open class CompileToBitcode @Inject constructor(
         @Internal val srcRoot: File,
@@ -85,7 +87,9 @@ open class CompileToBitcode @Inject constructor(
     @get:Input
     val compilerFlags: List<String>
         get() {
-            val commonFlags = listOf("-gdwarf-2", "-c", "-emit-llvm") + headersDirs.map { "-I$it" }
+            val commonFlags = listOfNotNull(
+                    "-gdwarf-2".takeIf { project.kotlinBuildProperties.isNativeRuntimeDebugInfoEnabled },
+                    "-c", "-emit-llvm") + headersDirs.map { "-I$it" }
             val sanitizerFlags = when (sanitizer) {
                 null -> listOf()
                 SanitizerKind.ADDRESS -> listOf("-fsanitize=address")