Write proper start label for loop parameter

compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java

@@ -627,7 +627,7 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
 
         // for (e : E in c) {...}
         protected final KtForExpression forExpression;
-        private final Label bodyStart = new Label();
+        private final Label loopParameterStartLabel = new Label();
         private final Label bodyEnd = new Label();
         private final List<Runnable> leaveVariableTasks = Lists.newArrayList();
 
@@ -667,7 +667,7 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
                         myFrameMap.leave(parameterDescriptor);
                         v.visitLocalVariable(parameterDescriptor.getName().asString(),
                                              loopParameterType.getDescriptor(), null,
-                                             bodyStart, bodyEnd,
+                                             loopParameterStartLabel, bodyEnd,
                                              loopParameterVar);
                     }
                 });
@@ -687,9 +687,8 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
         public abstract void checkPreCondition(@NotNull Label loopExit);
 
         public void beforeBody() {
-            v.mark(bodyStart);
-
             assignToLoopParameter();
+            v.mark(loopParameterStartLabel);
 
             if (forExpression.getLoopParameter() == null) {
                 KtDestructuringDeclaration multiParameter = forExpression.getDestructuringParameter();

compiler/testData/codegen/bytecodeText/forLoop/loopVarInterval.kt

@@ -0,0 +1,9 @@
+fun f() {
+    for (c in "123") {
+        print(c)
+    }
+}
+
+// 1 ISTORE 0\s+L3
+// 1 ILOAD 0\s+INVOKEVIRTUAL java/io/PrintStream.print \(C\)V
+// 1 LOCALVARIABLE c C L3 L8 0

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

@@ -835,6 +835,12 @@ public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/bytecodeText/forLoop"), Pattern.compile("^(.+)\\.kt$"), true);
         }
 
+        @TestMetadata("loopVarInterval.kt")
+        public void testLoopVarInterval() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/forLoop/loopVarInterval.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("primitiveLiteralRange1.kt")
         public void testPrimitiveLiteralRange1() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/forLoop/primitiveLiteralRange1.kt");