JVM_IR: partially fix inline methods using captured crossinline lambdas

The fields containing crossinline lambdas should be package-private to
avoid generating synthetic accessors, which break object regeneration.

Note that the inline methods cannot actually be called, as call sites
will attempt to read the captured lambda from a field through a *copy*
of the local containing the object, so these reads will not be inlined,
causing an exception at runtime:

    inline fun f(crossinline g: () -> Unit) = object : I {
        inline fun h() = g()
        // effectively `val tmp = this; return tmp.$g()`:
        override fun run() = h()
    }

    f {}.run() // NoSuchFieldError: $g

This particular example can be fixed by reusing locals for receiver
parameters in IrInlineCodegen, but explicitly assigning `this` to
another variable and calling an inline method on it will break it again.
(This is only applicable to the JVM_IR backend, as the non-IR one fails
to generate `f` at all for some other reason.)

compiler/testData/codegen/box/coroutines/javaInterop/objectWithSeveralSuspends.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND_FIR: JVM_IR
-// IGNORE_BACKEND: JVM_IR
 // TARGET_BACKEND: JVM
 // COMMON_COROUTINES_TEST
 // WITH_RUNTIME

compiler/testData/codegen/box/coroutines/tailCallOptimizations/crossinline_ir.txt

@@ -89,7 +89,7 @@ public final class CrossinlineKt$consumeEach$2$send$1 {
 
 @kotlin.Metadata
 public final class CrossinlineKt$consumeEach$2 {
-    private synthetic final field $action: kotlin.jvm.functions.Function2
+    synthetic final @org.jetbrains.annotations.NotNull field $action: kotlin.jvm.functions.Function2
     inner class CrossinlineKt$consumeEach$2
     inner class CrossinlineKt$consumeEach$2$send$1
     public method <init>(p0: kotlin.jvm.functions.Function2): void
@@ -355,7 +355,7 @@ public final class CrossinlineKt$source$1$consume$1 {
 
 @kotlin.Metadata
 public final class CrossinlineKt$source$1 {
-    private synthetic final field $action: kotlin.jvm.functions.Function2
+    synthetic final @org.jetbrains.annotations.NotNull field $action: kotlin.jvm.functions.Function2
     inner class CrossinlineKt$source$1
     inner class CrossinlineKt$source$1$consume$1
     public method <init>(p0: kotlin.jvm.functions.Function2): void

compiler/testData/codegen/box/coroutines/tailCallOptimizations/innerObjectRetransformation_ir.txt

@@ -65,7 +65,7 @@ public final class flow/InnerObjectRetransformationKt$collect$2$emit$1 {
 
 @kotlin.Metadata
 public final class flow/InnerObjectRetransformationKt$collect$2 {
-    private synthetic final field $action: kotlin.jvm.functions.Function2
+    synthetic final @org.jetbrains.annotations.NotNull field $action: kotlin.jvm.functions.Function2
     inner class flow/InnerObjectRetransformationKt$collect$2
     inner class flow/InnerObjectRetransformationKt$collect$2$emit$1
     public method <init>(p0: kotlin.jvm.functions.Function2): void
@@ -86,7 +86,7 @@ public final class flow/InnerObjectRetransformationKt$flow$1$collect$1 {
 
 @kotlin.Metadata
 public final class flow/InnerObjectRetransformationKt$flow$1 {
-    private synthetic final field $block: kotlin.jvm.functions.Function2
+    synthetic final @org.jetbrains.annotations.NotNull field $block: kotlin.jvm.functions.Function2
     inner class flow/InnerObjectRetransformationKt$flow$1
     inner class flow/InnerObjectRetransformationKt$flow$1$collect$1
     public method <init>(p0: kotlin.jvm.functions.Function2): void

compiler/testData/codegen/box/coroutines/tailCallOptimizations/unit/override5_ir.txt

@@ -48,7 +48,7 @@ public final class Override5Kt$inlineMe$1$generic$2 {
 
 @kotlin.Metadata
 public final class Override5Kt$inlineMe$1 {
-    private synthetic final field $c: kotlin.jvm.functions.Function1
+    synthetic final @org.jetbrains.annotations.NotNull field $c: kotlin.jvm.functions.Function1
     inner class Override5Kt$inlineMe$1
     inner class Override5Kt$inlineMe$1$generic$1
     inner class Override5Kt$inlineMe$1$generic$2

compiler/testData/codegen/boxInline/anonymousObject/withInlineMethod.kt

@@ -0,0 +1,20 @@
+// FILE: 1.kt
+package test
+
+interface I {
+    fun f(): String
+}
+
+inline fun test(crossinline h: () -> String) = object : I {
+    // TODO: actually call g() in f() -- currently, the inliner fails to detect
+    //       an inlined read of h's field because it uses a copy of `this`
+    //       as a receiver
+    override fun f(): String = h()
+    inline fun g(): String = h()
+}
+
+// FILE: 2.kt
+
+import test.*
+
+fun box(): String = test { "OK" }.f()

compiler/testData/codegen/bytecodeListing/coroutines/tcoContinuation_ir.txt

@@ -21,7 +21,7 @@ public final class TcoContinuationKt$collect$2$emit$1 {
 
 @kotlin.Metadata
 public final class TcoContinuationKt$collect$2 {
-    private synthetic final field $action: kotlin.jvm.functions.Function2
+    synthetic final @org.jetbrains.annotations.NotNull field $action: kotlin.jvm.functions.Function2
     inner class TcoContinuationKt$collect$2
     inner class TcoContinuationKt$collect$2$emit$1
     public method <init>(p0: kotlin.jvm.functions.Function2): void
@@ -42,7 +42,7 @@ public final class TcoContinuationKt$flow$1$collect$1 {
 
 @kotlin.Metadata
 public final class TcoContinuationKt$flow$1 {
-    private synthetic final field $block: kotlin.jvm.functions.Function2
+    synthetic final @org.jetbrains.annotations.NotNull field $block: kotlin.jvm.functions.Function2
     inner class TcoContinuationKt$flow$1
     inner class TcoContinuationKt$flow$1$collect$1
     public method <init>(p0: kotlin.jvm.functions.Function2): void