[K/N] Move framework interface generation to "Produce Output" phase

It allows to invoke interface generation even if we don't compile a
binary.

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/CompilerOutput.kt

@@ -181,7 +181,9 @@ internal fun produceOutput(context: Context) {
     val config = context.config.configuration
     val tempFiles = context.config.tempFiles
     val produce = config.get(KonanConfigKeys.PRODUCE)
-
+    if (produce == CompilerOutputKind.FRAMEWORK) {
+        context.objCExport.produceFrameworkInterface()
+    }
     when (produce) {
         CompilerOutputKind.STATIC,
         CompilerOutputKind.DYNAMIC,

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/objcexport/ObjCExport.kt

@@ -47,8 +47,6 @@ internal class ObjCExport(val context: Context, symbolTable: SymbolTable) {
     private fun produceInterface(): ObjCExportedInterface? {
         if (!target.family.isAppleFamily) return null
 
-        if (!context.config.produce.isFinalBinary) return null
-
         // TODO: emit RTTI to the same modules as classes belong to.
         //   Not possible yet, since ObjCExport translates the entire "world" API at once
         //   and can't do this per-module, e.g. due to global name conflict resolution.
@@ -98,16 +96,21 @@ internal class ObjCExport(val context: Context, symbolTable: SymbolTable) {
 
         val objCCodeGenerator = ObjCExportCodeGenerator(codegen, namer, mapper)
 
-        if (exportedInterface != null) {
-            produceFrameworkSpecific(exportedInterface.headerLines)
-
-            exportedInterface.generateWorkaroundForSwiftSR10177()
-        }
+        exportedInterface?.generateWorkaroundForSwiftSR10177()
 
         objCCodeGenerator.generate(codeSpec)
         objCCodeGenerator.dispose()
     }
 
+    /**
+     * Populate framework directory with headers, module and info.plist.
+     */
+    fun produceFrameworkInterface() {
+        if (exportedInterface != null) {
+            produceFrameworkSpecific(exportedInterface.headerLines)
+        }
+    }
+
     private fun produceFrameworkSpecific(headerLines: List<String>) {
         val framework = File(context.config.outputFile)
         val frameworkContents = when(target.family) {