Fix last if-statement in block codegen

#KT-3203 Fixed

compiler/testData/codegen/regressions/kt3203_1.kt

@@ -0,0 +1,19 @@
+fun testIf() {
+    val condition = true
+    val result = if (condition) {
+        val hello: String? = "hello"
+        if (hello == null) {
+            false
+        }
+        else {
+            true
+        }
+    }
+    else true
+    if (!result) throw AssertionError("result is false")
+}
+
+fun box(): String {
+    testIf()
+    return "OK"
+}

compiler/testData/codegen/regressions/kt3203_2.kt

@@ -0,0 +1,20 @@
+fun check1() {
+    val result = if (true) {
+        if (true) 1 else 2
+    }
+    else 3
+    if (result != 1) throw AssertionError("result: $result")
+}
+
+fun check2() {
+    val result = if (true)
+        if (true) 1 else 2
+    else 3
+    if (result != 1) throw AssertionError("result: $result")
+}
+
+fun box(): String {
+    check1()
+    check2()
+    return "OK"
+}