Intention "Convert to expression body"

idea/testData/intentions/convertToExpressionBody/beforeAssignment.kt

@@ -0,0 +1,8 @@
+// "class org.jetbrains.jet.plugin.intentions.ConvertToExpressionBodyAction" "false"
+
+var a = 1
+var b = 2
+
+fun foo() {
+    <caret>a = b
+}