KT-6916 Slow bytecode for downTo iteration like for (i in max downTo min)

#KT-6916 fixed

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

@@ -107,12 +107,7 @@ public class RangeCodegenUtil {
             @NotNull ImmutableMap<FqName, PrimitiveType> map
     ) {
         ClassifierDescriptor declarationDescriptor = rangeOrProgression.getConstructor().getDeclarationDescriptor();
-        assert declarationDescriptor != null;
-        if (declarationDescriptor != KotlinBuiltIns.getInstance().getBuiltInsPackageScope().getClassifier(declarationDescriptor.getName())) {
-            // Must be a standard library class
-            return null;
-        }
-        return map.get(DescriptorUtils.getFqNameSafe(declarationDescriptor));
+        return declarationDescriptor == null ? null : map.get(DescriptorUtils.getFqNameSafe(declarationDescriptor));
     }
 
     @Nullable

compiler/testData/codegen/bytecodeText/forLoop/primitiveLiteralRange1.kt

@@ -0,0 +1,8 @@
+fun f() {
+    for (i in 1..2) {
+    }
+}
+
+// 0 iterator
+// 0 getStart
+// 0 getEnd

compiler/testData/codegen/bytecodeText/forLoop/primitiveLiteralRange2.kt

@@ -0,0 +1,8 @@
+fun f(a: Int, b: Int) {
+    for (i in a..b) {
+    }
+}
+
+// 0 iterator
+// 0 getStart
+// 0 getEnd

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

@@ -0,0 +1,11 @@
+fun f() {
+    for (i in 0..5 step 2) {
+    }
+    for (i in 5 downTo 1) {
+    }
+}
+
+// 0 iterator
+// 2 getStart
+// 2 getEnd
+// 2 getIncrement

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

@@ -0,0 +1,8 @@
+fun f(r: IntRange) {
+    for (i in r) {
+    }
+}
+
+// 0 iterator
+// 1 getStart
+// 1 getEnd

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

@@ -35,6 +35,7 @@ import java.util.regex.Pattern;
         BytecodeTextTestGenerated.Constants.class,
         BytecodeTextTestGenerated.DeadCodeElimination.class,
         BytecodeTextTestGenerated.DirectInvoke.class,
+        BytecodeTextTestGenerated.ForLoop.class,
         BytecodeTextTestGenerated.Inline.class,
         BytecodeTextTestGenerated.LazyCodegen.class,
         BytecodeTextTestGenerated.LineNumbers.class,
@@ -405,6 +406,39 @@ public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
         }
     }
 
+    @TestMetadata("compiler/testData/codegen/bytecodeText/forLoop")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class ForLoop extends AbstractBytecodeTextTest {
+        public void testAllFilesPresentInForLoop() throws Exception {
+            JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/bytecodeText/forLoop"), Pattern.compile("^(.+)\\.kt$"), true);
+        }
+
+        @TestMetadata("primitiveLiteralRange1.kt")
+        public void testPrimitiveLiteralRange1() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/forLoop/primitiveLiteralRange1.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("primitiveLiteralRange2.kt")
+        public void testPrimitiveLiteralRange2() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/forLoop/primitiveLiteralRange2.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("primitiveProgression.kt")
+        public void testPrimitiveProgression() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/forLoop/primitiveProgression.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("primitiveRange.kt")
+        public void testPrimitiveRange() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/forLoop/primitiveRange.kt");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("compiler/testData/codegen/bytecodeText/inline")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)