[Native] Add simple symbol mechanism to konan.properties

Java Properties format is extremely trivial and does not support any
kind of references or variables. It makes konan.properties repetitive.
This commits adds support of perl-like `$` sigil which allows to
reference properties inside values.

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/nativeToolRunners.kt

@@ -12,6 +12,7 @@ import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider
 import org.jetbrains.kotlin.gradle.plugin.mpp.isAtLeast
 import org.jetbrains.kotlin.gradle.utils.NativeCompilerDownloader
 import org.jetbrains.kotlin.konan.CompilerVersion
+import org.jetbrains.kotlin.konan.properties.resolvablePropertyString
 import org.jetbrains.kotlin.konan.target.HostManager
 import org.jetbrains.kotlin.konan.target.KonanTarget
 import org.jetbrains.kotlin.konan.util.DependencyDirectories
@@ -104,7 +105,7 @@ internal abstract class AbstractKotlinNativeCInteropRunner(toolName: String, pro
                 project.file("${project.konanHome}/konan/konan.properties").inputStream().use(::load)
             }
 
-            konanProperties.getProperty("llvmHome.mingw_x64")?.let { toolchainDir ->
+            konanProperties.resolvablePropertyString("llvmHome.mingw_x64")?.let { toolchainDir ->
                 DependencyDirectories.defaultDependenciesRoot
                     .resolve("$toolchainDir/bin")
                     .absolutePath