Pseudocode: Generate magics for cast expressions

compiler/frontend/src/org/jetbrains/jet/lang/cfg/JetControlFlowProcessor.java

@@ -1203,7 +1203,9 @@ public class JetControlFlowProcessor {
             JetExpression left = expression.getLeft();
             if (operationType == JetTokens.COLON || operationType == JetTokens.AS_KEYWORD || operationType == JetTokens.AS_SAFE) {
                 generateInstructions(left);
-                copyValue(left, expression);
+                if (builder.getBoundValue(left) != null) {
+                    createNonSyntheticValue(expression, MagicKind.CAST, left);
+                }
             }
             else {
                 visitJetElement(expression);

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/instructions/eval/operationInstructions.kt

@@ -139,6 +139,7 @@ public enum class MagicKind {
     NOT_NULL_ASSERTION
     EQUALS_IN_WHEN_CONDITION
     IS
+    CAST
     CALLABLE_REFERENCE
     // implicit operations
     LOOP_RANGE_ITERATION