JVM_IR: refine the condition for mangling names of multifile members

Private $$forInline versions of public suspend functions should not
be mangled. (Note that there are no $$forInline versions of private
suspend functions, as those are effectively inline-only.)

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/MethodSignatureMapper.kt

@@ -112,8 +112,8 @@ class MethodSignatureMapper(private val context: JvmBackendContext) {
         val newName = JvmCodegenUtil.sanitizeNameIfNeeded(name, context.state.languageVersionSettings)
 
         if (function.isTopLevel) {
-            if (Visibilities.isPrivate(function.visibility) && newName != "<clinit>" &&
+            if (Visibilities.isPrivate(if (function.isSuspend) function.suspendFunctionOriginal().visibility else function.visibility) &&
-                (function.parent as? IrClass)?.attributeOwnerId in context.multifileFacadeForPart
+                newName != "<clinit>" && (function.parent as? IrClass)?.attributeOwnerId in context.multifileFacadeForPart
             ) {
                 return "$newName$${function.parentAsClass.name.asString()}"
             }

compiler/testData/codegen/boxInline/suspend/inlineSuspendInMultifileClass.kt

@@ -0,0 +1,34 @@
+// FILE: test.kt
+// WITH_RUNTIME
+// WITH_COROUTINES
+// NO_CHECK_LAMBDA_INLINING
+// TARGET_BACKEND: JVM
+// !INHERIT_MULTIFILE_PARTS
+
+// The lambda in box() attempts to store the result in a null Ref for some reason.
+// IGNORE_BACKEND: JVM
+// IGNORE_BACKEND_MULTI_MODULE: JVM
+
+@file:JvmMultifileClass
+@file:JvmName("XKt")
+
+suspend fun suspendHere() {}
+
+suspend inline fun test(c: suspend () -> String): String {
+    suspendHere()
+    val result = c()
+    suspendHere()
+    return result
+}
+
+// FILE: box.kt
+import kotlin.coroutines.*
+import helpers.*
+
+fun box() : String {
+    var res = "fail"
+    suspend {
+        res = test { "OK" }
+    }.startCoroutine(EmptyContinuation)
+    return res
+}

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxInlineCodegenTestGenerated.java

@@ -3718,6 +3718,11 @@ public class BlackBoxInlineCodegenTestGenerated extends AbstractBlackBoxInlineCo
             runTestWithPackageReplacement("compiler/testData/codegen/boxInline/suspend/inlineSuspendContinuation.kt", "kotlin.coroutines");
         }
 
+        @TestMetadata("inlineSuspendInMultifileClass.kt")
+        public void testInlineSuspendInMultifileClass() throws Exception {
+            runTest("compiler/testData/codegen/boxInline/suspend/inlineSuspendInMultifileClass.kt");
+        }
+
         @TestMetadata("inlineSuspendOfCrossinlineOrdinary.kt")
         public void testInlineSuspendOfCrossinlineOrdinary_1_2() throws Exception {
             runTestWithPackageReplacement("compiler/testData/codegen/boxInline/suspend/inlineSuspendOfCrossinlineOrdinary.kt", "kotlin.coroutines.experimental");

compiler/tests/org/jetbrains/kotlin/codegen/CompileKotlinAgainstInlineKotlinTestGenerated.java

@@ -3718,6 +3718,11 @@ public class CompileKotlinAgainstInlineKotlinTestGenerated extends AbstractCompi
             runTestWithPackageReplacement("compiler/testData/codegen/boxInline/suspend/inlineSuspendContinuation.kt", "kotlin.coroutines");
         }
 
+        @TestMetadata("inlineSuspendInMultifileClass.kt")
+        public void testInlineSuspendInMultifileClass() throws Exception {
+            runTest("compiler/testData/codegen/boxInline/suspend/inlineSuspendInMultifileClass.kt");
+        }
+
         @TestMetadata("inlineSuspendOfCrossinlineOrdinary.kt")
         public void testInlineSuspendOfCrossinlineOrdinary_1_2() throws Exception {
             runTestWithPackageReplacement("compiler/testData/codegen/boxInline/suspend/inlineSuspendOfCrossinlineOrdinary.kt", "kotlin.coroutines.experimental");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxInlineCodegenTestGenerated.java

@@ -3683,6 +3683,11 @@ public class IrBlackBoxInlineCodegenTestGenerated extends AbstractIrBlackBoxInli
             runTestWithPackageReplacement("compiler/testData/codegen/boxInline/suspend/inlineSuspendContinuation.kt", "kotlin.coroutines");
         }
 
+        @TestMetadata("inlineSuspendInMultifileClass.kt")
+        public void testInlineSuspendInMultifileClass() throws Exception {
+            runTest("compiler/testData/codegen/boxInline/suspend/inlineSuspendInMultifileClass.kt");
+        }
+
         @TestMetadata("inlineSuspendOfCrossinlineOrdinary.kt")
         public void testInlineSuspendOfCrossinlineOrdinary_1_3() throws Exception {
             runTestWithPackageReplacement("compiler/testData/codegen/boxInline/suspend/inlineSuspendOfCrossinlineOrdinary.kt", "kotlin.coroutines");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrCompileKotlinAgainstInlineKotlinTestGenerated.java

@@ -3683,6 +3683,11 @@ public class IrCompileKotlinAgainstInlineKotlinTestGenerated extends AbstractIrC
             runTestWithPackageReplacement("compiler/testData/codegen/boxInline/suspend/inlineSuspendContinuation.kt", "kotlin.coroutines");
         }
 
+        @TestMetadata("inlineSuspendInMultifileClass.kt")
+        public void testInlineSuspendInMultifileClass() throws Exception {
+            runTest("compiler/testData/codegen/boxInline/suspend/inlineSuspendInMultifileClass.kt");
+        }
+
         @TestMetadata("inlineSuspendOfCrossinlineOrdinary.kt")
         public void testInlineSuspendOfCrossinlineOrdinary_1_3() throws Exception {
             runTestWithPackageReplacement("compiler/testData/codegen/boxInline/suspend/inlineSuspendOfCrossinlineOrdinary.kt", "kotlin.coroutines");