[FIR] Fix false positive "return required" for if/else with inlined return in branch

^KT-49289 Fixed

compiler/testData/diagnostics/tests/inline/inlinedReturnInBranch.kt

@@ -0,0 +1,20 @@
+// FIR_IDENTICAL
+// https://youtrack.jetbrains.com/issue/KT-49289
+
+inline fun <T> myRun(f: () -> T): T = f()
+
+fun foo(): Int {
+    myRun {
+        return 24
+    }
+}
+
+fun bar(arg: Boolean): Int {
+    if (arg) {
+        return 42
+    } else {
+        myRun {
+            return 24
+        }
+    }
+}

compiler/testData/diagnostics/tests/inline/inlinedReturnInBranch.txt

@@ -0,0 +1,5 @@
+package
+
+public fun bar(/*0*/ arg: kotlin.Boolean): kotlin.Int
+public fun foo(): kotlin.Int
+public inline fun </*0*/ T> myRun(/*0*/ f: () -> T): T