Smart casts for local variables not captured in a closure and not changed in a loop, see #KT-3175.

isLocalVariable added. Assignment / initialization analysis.
Control whether a variable is changed in a loop at the beginning and at the end of the loop.
Control whether a variable is captured in a closure. #KT-3175  Fixed. #KT-2266  Fixed.
Tests for variable null safety and for variables is/as operations.
Loop / closure / variable property tests are included.
Old tests changed in accordance with KT-3175. In particular, all three of testSmartcastImpossible were fixed.

idea/testData/quickfix/typeMismatch/casts/afterSmartcastImpossible1.kt

@@ -1,10 +1,14 @@
 // "Cast expression 'a' to 'Foo'" "true"
+
 trait Foo {
     fun plus(x: Any) : Foo
 }
 
-fun foo(_a: Any): Any {
-    var a = _a
+open class MyClass {
+    public open val a: Any = "42"
+}
+
+fun MyClass.foo(): Any {
     if (a is Foo) {
         return a as Foo + a
     }

idea/testData/quickfix/typeMismatch/casts/afterSmartcastImpossible2.kt

@@ -1,10 +1,14 @@
 // "Cast expression 'a' to 'Foo'" "true"
+
 trait Foo {
     fun not() : Foo
 }
 
-fun foo(_a: Any): Any {
-    var a = _a
+open class MyClass {
+    public open val a: Any = "42"
+}
+
+fun MyClass.foo(): Any {
     if (a is Foo) {
         return !(a as Foo)
     }

idea/testData/quickfix/typeMismatch/casts/afterSmartcastImpossible3.kt

@@ -1,11 +1,15 @@
 // "Cast expression 'x' to 'Foo<*>'" "true"
+
 trait Foo<T: Number> {
-    fun foo()
+    fun bar()
 }
 
-fun bar(_x: Any) {
-    var x = _x
+open class MyClass {
+    public open val x: Any = "42"
+}
+
+fun MyClass.bar() {
     if (x is Foo<*>) {
-        (x as Foo<*>).foo()
+        (x as Foo<*>).bar()
     }
 }

idea/testData/quickfix/typeMismatch/casts/beforeSmartcastImpossible1.kt

@@ -1,10 +1,14 @@
 // "Cast expression 'a' to 'Foo'" "true"
+
 trait Foo {
     fun plus(x: Any) : Foo
 }
 
-fun foo(_a: Any): Any {
-    var a = _a
+open class MyClass {
+    public open val a: Any = "42"
+}
+
+fun MyClass.foo(): Any {
     if (a is Foo) {
         return a<caret> + a
     }

idea/testData/quickfix/typeMismatch/casts/beforeSmartcastImpossible2.kt

@@ -1,10 +1,14 @@
 // "Cast expression 'a' to 'Foo'" "true"
+
 trait Foo {
     fun not() : Foo
 }
 
-fun foo(_a: Any): Any {
-    var a = _a
+open class MyClass {
+    public open val a: Any = "42"
+}
+
+fun MyClass.foo(): Any {
     if (a is Foo) {
         return !a<caret>
     }

idea/testData/quickfix/typeMismatch/casts/beforeSmartcastImpossible3.kt

@@ -1,11 +1,15 @@
 // "Cast expression 'x' to 'Foo<*>'" "true"
+
 trait Foo<T: Number> {
-    fun foo()
+    fun bar()
 }
 
-fun bar(_x: Any) {
-    var x = _x
+open class MyClass {
+    public open val x: Any = "42"
+}
+
+fun MyClass.bar() {
     if (x is Foo<*>) {
-        x<caret>.foo()
+        x<caret>.bar()
     }
 }