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

#KT-16032 Fixed

idea/formatter/src/org/jetbrains/kotlin/idea/formatter/KotlinSpacingBuilder.kt

@@ -21,6 +21,7 @@ import com.intellij.formatting.DependentSpacingRule.Anchor
 import com.intellij.formatting.DependentSpacingRule.Trigger
 import com.intellij.lang.ASTNode
 import com.intellij.openapi.util.TextRange
+import com.intellij.psi.PsiComment
 import com.intellij.psi.codeStyle.CommonCodeStyleSettings
 import com.intellij.psi.tree.IElementType
 import com.intellij.psi.tree.TokenSet
@@ -80,10 +81,12 @@ class KotlinSpacingBuilder(val commonCodeStyleSettings: CommonCodeStyleSettings,
 
         fun emptyLinesIfLineBreakInLeft(emptyLines: Int, numberOfLineFeedsOtherwise: Int = 1, numSpacesOtherwise: Int = 0) {
             newRule { parent: ASTBlock, left: ASTBlock, right: ASTBlock ->
+                val lastChild = left.node?.psi?.lastChild
+                val leftEndsWithComment = lastChild is PsiComment && lastChild.tokenType == KtTokens.EOL_COMMENT
                 val dependentSpacingRule = DependentSpacingRule(Trigger.HAS_LINE_FEEDS).registerData(Anchor.MIN_LINE_FEEDS, emptyLines + 1)
                 spacingBuilderUtil.createLineFeedDependentSpacing(numSpacesOtherwise,
                                                                   numSpacesOtherwise,
-                                                                  numberOfLineFeedsOtherwise,
+                                                                  if (leftEndsWithComment) Math.max(1, numberOfLineFeedsOtherwise) else numberOfLineFeedsOtherwise,
                                                                   commonCodeStyleSettings.KEEP_LINE_BREAKS,
                                                                   commonCodeStyleSettings.KEEP_BLANK_LINES_IN_DECLARATIONS,
                                                                   left.textRange,