[K/N][Tests] Patch package names also for .def files

To separate interop modules to different packages,
.def files should be treated similarly to .kt files:
1) package directive should be prepended with test-specific synthetic package,
or, if, absent, package directive with synthetic package should be added.
2) in .kt files, import directives and fully-qualified import from interop modules
should be prepended with same test-specific synthetic package.

compiler/testData/codegen/box/cinterop/basics/3.kt

@@ -4,14 +4,14 @@
  */
 // TARGET_BACKEND: NATIVE
 // MODULE: cinterop
-// FILE: cstdlib_3.def
+// FILE: cstdlib.def
 headers = stdlib.h
 
 // MODULE: main(cinterop)
 // FILE: main.kt
 @file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
 
-import cstdlib_3.*
+import cstdlib.*
 import kotlinx.cinterop.*
 import kotlin.test.*