Add tests for KEEP_LINE_BREAKS

idea/testData/formatter/KeepLineBreak.after.inv.kt

@@ -0,0 +1,18 @@
+fun foo() {
+    if
+            (true) {
+
+    }
+
+    while
+            (true) {
+
+    }
+
+    for
+    (i in 0..42) {
+
+    }
+}
+
+// SET_FALSE: KEEP_LINE_BREAKS

idea/testData/formatter/KeepLineBreak.after.kt

@@ -0,0 +1,15 @@
+fun foo() {
+    if (true) {
+
+    }
+
+    while (true) {
+
+    }
+
+    for (i in 0..42) {
+
+    }
+}
+
+// SET_FALSE: KEEP_LINE_BREAKS

idea/testData/formatter/KeepLineBreak.kt

@@ -0,0 +1,18 @@
+fun foo() {
+    if
+    (true) {
+
+    }
+
+    while
+    (true) {
+
+    }
+
+    for
+    (i in 0..42) {
+
+    }
+}
+
+// SET_FALSE: KEEP_LINE_BREAKS

idea/tests/org/jetbrains/kotlin/formatter/FormatterTestGenerated.java

@@ -404,6 +404,12 @@ public class FormatterTestGenerated extends AbstractFormatterTest {
             doTest(fileName);
         }
 
+        @TestMetadata("KeepLineBreak.after.kt")
+        public void testKeepLineBreak() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/formatter/KeepLineBreak.after.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("LabeledExpression.after.kt")
         public void testLabeledExpression() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/formatter/LabeledExpression.after.kt");
@@ -1076,6 +1082,12 @@ public class FormatterTestGenerated extends AbstractFormatterTest {
             doTestInverted(fileName);
         }
 
+        @TestMetadata("KeepLineBreak.after.inv.kt")
+        public void testKeepLineBreak() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/formatter/KeepLineBreak.after.inv.kt");
+            doTestInverted(fileName);
+        }
+
         @TestMetadata("LambdaArrow.after.inv.kt")
         public void testLambdaArrow() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/formatter/LambdaArrow.after.inv.kt");