backend/tests: add more interop tests

backend.native/tests/build.gradle

@@ -1081,6 +1081,18 @@ kotlinNativeInterop {
         headers 'sys/stat.h'
         target 'native'
     }
+
+    cstdlib {
+        pkg 'cstdlib'
+        headers 'stdlib.h'
+        target 'native'
+    }
+
+    cstdio {
+        defFile 'interop/basics/cstdio.def'
+        target 'native'
+        compilerOpts '-D_POSIX_SOURCE' // Exclude Darwin extensions causing link errors.
+    }
 }
 
 task interop0(type: RunInteropKonanTest) {
@@ -1088,3 +1100,15 @@ task interop0(type: RunInteropKonanTest) {
     source = "interop/basics/0.kt"
     interop = 'sysstat'
 }
+
+task interop1(type: RunInteropKonanTest) {
+    goldValue = "257\n"
+    source = "interop/basics/1.kt"
+    interop = 'cstdlib'
+}
+
+task interop2(type: RunInteropKonanTest) {
+    goldValue = "Hello\n"
+    source = "interop/basics/2.kt"
+    interop = 'cstdio'
+}

backend.native/tests/interop/basics/1.kt

@@ -0,0 +1,5 @@
+import cstdlib.*
+
+fun main(args: Array<String>) {
+    println(atoi("257"))
+}

backend.native/tests/interop/basics/2.kt

@@ -0,0 +1,5 @@
+import cstdio.*
+
+fun main(args: Array<String>) {
+    puts("Hello")
+}

backend.native/tests/interop/basics/cstdio.def

@@ -0,0 +1,2 @@
+headers = stdio.h
+excludedFunctions = _IO_flockfile _IO_funlockfile _IO_ftrylockfile _IO_cleanup_region_start _IO_cleanup_region_end