backend: add tests:

* test for uninitialized vals
* test initializers3: global `var` of reference type
* expression_as_statement (disabled): using type operator as statement

Also enable test break1.

backend.native/tests/build.gradle

@@ -681,6 +681,11 @@ task scope1(type: RunKonanTest) {
     source = "codegen/dataflow/scope1.kt"
 }
 
+task uninitialized_val(type: RunKonanTest) {
+    goldValue = "1\n2\n"
+    source = "codegen/dataflow/uninitialized_val.kt"
+}
+
 task try1(type: RunKonanTest) {
     goldValue = "5\n"
     source = "codegen/try/try1.kt"
@@ -712,7 +717,6 @@ task break_continue(type: RunKonanTest) {
 }
 
 task break1(type: RunKonanTest) {
-    disabled = true
     goldValue = "Body\nDone\n"
     source = "codegen/controlflow/break1.kt"
 }
@@ -842,3 +846,14 @@ task initializers2(type: RunKonanTest) {
                 "globalValue3\n"
     source = "runtime/basic/initializers2.kt"
 }
+
+task initializers3(type: RunKonanTest) {
+    goldValue = "42\n"
+    source = "runtime/basic/initializers3.kt"
+}
+
+task expression_as_statement(type: RunKonanTest) {
+    disabled = true
+    goldValue = "Ok\n"
+    source = "codegen/basics/expression_as_statement.kt"
+}

backend.native/tests/codegen/basics/expression_as_statement.kt

@@ -0,0 +1,14 @@
+fun foo() {
+    Any() as String
+}
+
+fun main(args: Array<String>) {
+    try {
+        foo()
+    } catch (e: Throwable) {
+        println("Ok")
+        return
+    }
+
+    println("Fail")
+}

backend.native/tests/codegen/dataflow/uninitialized_val.kt

@@ -0,0 +1,17 @@
+fun foo(b: Boolean): Int {
+    val x: Int
+    if (b) {
+        x = 1
+    } else {
+        x = 2
+    }
+
+    return x
+}
+
+fun main(args: Array<String>) {
+    val uninitializedUnused: Int
+
+    println(foo(true))
+    println(foo(false))
+}

backend.native/tests/runtime/basic/initializers3.kt

@@ -0,0 +1,7 @@
+class Foo(val bar: Int)
+
+var x = Foo(42)
+
+fun main(args: Array<String>) {
+    println(x.bar)
+}