Multiple fixes for try-catch-finally codegen

#KT-2259 Fixed
 #KT-2577 Fixed

compiler/testData/codegen/controlStructures/tryCatchFinallyChain.kt

@@ -0,0 +1,19 @@
+fun box() : String {
+    try {
+    } finally {
+        try {
+            try {
+            } finally {
+                try {
+                } finally {
+                }
+            }
+        } catch (e: Exception) {
+            try {
+            } catch (f: Exception) {
+            } finally {
+            }
+        }
+        return "OK"
+    }
+}

compiler/testData/codegen/regressions/kt2259.kt

@@ -0,0 +1,10 @@
+fun main(args: Array<String>) {
+    try {
+    } finally {
+        try {
+        } catch (e: Throwable) {
+        }
+    }
+}
+
+fun box() = "OK"

compiler/testData/codegen/regressions/kt2577.kt

@@ -0,0 +1,12 @@
+fun foo(): Int {
+    try {
+    } finally {
+        try {
+            return 1
+        } catch (e: Throwable) {
+            return 2
+        }
+    }
+}
+
+fun box() = if (foo() == 1) "OK" else "Fail"