A test to check we don't throw away a library dependency only because it

it a default lib not needed in the main program.

backend.native/tests/build.gradle

@@ -1227,6 +1227,12 @@ task link_default_libs(type: RunKonanTest) {
     source = "link/default/default.kt"
 }
 
+task no_purge_for_dependencies(type: LinkKonanTest) {
+    goldValue = "linked library\nand symbols from posix available: 17; 1.0\n"
+    source = "link/purge1/prog.kt"
+    lib = "link/purge1/lib.kt"
+}
+
 task for0(type: RunKonanTest) {
     goldValue = "2\n3\n4\n"
     source = "runtime/basic/for0.kt"

backend.native/tests/link/purge1/lib.kt

@@ -0,0 +1,8 @@
+import platform.posix.*
+
+fun foo() {
+    println("linked library")
+    val size: size_t = 17L
+    val e = fabs(1.toDouble())
+    println("and symbols from posix available: $size; $e")
+}

backend.native/tests/link/purge1/prog.kt

@@ -0,0 +1,4 @@
+
+fun main(args: Array<String>) {
+    foo()
+}