KT-37986 Force boxing of inline class returned from function reference

KT-37998 Provide KotlinType for safe call

compiler/testData/codegen/box/inlineClasses/callableReferences/kt37986.kt

@@ -0,0 +1,25 @@
+// IGNORE_BACKEND: JVM_IR
+// IGNORE_BACKEND_FIR: JVM_IR
+
+inline class R(val x: Any)
+
+fun useR(r: R) {
+    if (r.x as String != "OK") throw AssertionError("$r")
+}
+
+fun useR0(fn: () -> R) {
+    useR(fn())
+}
+
+fun useR1(r: R, fn: (R) -> R) {
+    useR(fn(r))
+}
+
+fun fnWithDefaultR(r: R = R("OK")) = r
+
+fun box(): String {
+    useR0(::fnWithDefaultR)
+    useR1(R("OK"), ::fnWithDefaultR)
+
+    return "OK"
+}

compiler/testData/codegen/box/inlineClasses/kt37998.kt

@@ -0,0 +1,13 @@
+inline class Z(val x: Int)
+
+class A {
+    fun foo() = Z(42)
+}
+
+fun test(a: A?) = a?.foo()!!
+
+fun box(): String {
+    val t = test(A())
+    if (t.x != 42) throw AssertionError("$t")
+    return "OK"
+}