Make loops generation lazy

As well as all other kinds of expressions

While it's not necessary in a sense that 'for' loop can not be plain expression,
i.e. it can't be an argument for safe-call etc., but laziness is still very convenient property.

E.g. within attached test they were generated twice in case of last expression
of coroutine block, because coroutine related codegen part is built upon
assumption that all expressions should be generated lazy.

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -4183,6 +4183,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
+        @TestMetadata("lastExpressionIsLoop.kt")
+        public void testLastExpressionIsLoop() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/coroutines/lastExpressionIsLoop.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("lastUnitExpression.kt")
         public void testLastUnitExpression() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/coroutines/lastUnitExpression.kt");