Don't extend to comments when a comment is being moved (KT-23461)

idea/testData/codeInsight/moveUpDown/expressions/comments.kt

@@ -0,0 +1,6 @@
+// MOVE: down
+fun foo() {
+    <caret>// Move me down
+    // 1
+    // 2
+}

idea/testData/codeInsight/moveUpDown/expressions/comments.kt.after

@@ -0,0 +1,6 @@
+// MOVE: down
+fun foo() {
+    // 1
+    <caret>// Move me down
+    // 2
+}