Don't merge two lines in formatter after line comment (KT-16032)

#KT-16032 Fixed

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

@@ -0,0 +1,33 @@
+enum class E1 { F, S, T }
+
+enum class E2 {
+    F, S, T
+}
+
+enum class E3 {
+    F, S, T
+}
+
+enum class E4 {
+    F {}, S, T
+}
+
+enum class E5 { F, S {}, T }
+
+enum class E6 {
+    F, S, T {}
+}
+
+enum class E7 {
+    F {
+
+    },
+    S, T
+}
+
+enum class E8 {
+    A, // A
+    B  // B
+}
+
+// SET_TRUE: KEEP_LINE_BREAKS

idea/testData/formatter/EmptyLineBetweenEnumEntries.after.kt

@@ -25,4 +25,11 @@ enum class E7 {
 
     },
     S, T
-}
+}
+
+enum class E8 {
+    A, // A
+    B  // B
+}
+
+// SET_TRUE: KEEP_LINE_BREAKS

idea/testData/formatter/EmptyLineBetweenEnumEntries.kt

@@ -22,4 +22,11 @@ enum class E7 {
     F {
 
     }, S, T
-}
+}
+
+enum class E8 {
+    A, // A
+    B  // B
+}
+
+// SET_TRUE: KEEP_LINE_BREAKS