Build: implement useBootstrapStdlib flag

Excludes stdlib projects from build and uses bootstrap stdlib artifacts

 #KT-29205

compiler/util/build.gradle.kts

@@ -7,7 +7,7 @@ plugins {
 jvmTarget = "1.6"
 
 dependencies {
-    compile(project(":kotlin-stdlib"))
+    compile(kotlinStdlib())
     compileOnly("org.jetbrains:annotations:13.0")
     compile(project(":core:deserialization"))
     compileOnly(intellijCoreDep()) { includeJars("intellij-core") }