New J2K: Add Block primitive

j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKVisitor.kt

@@ -7,4 +7,5 @@ interface JKVisitor<R, D>  {
     fun visitStatement(statement: JKStatement, data: D): R = visitElement(statement, data)
     fun visitLoop(loop: JKLoop, data: D): R = visitStatement(loop, data)
     fun visitDeclaration(declaration: JKDeclaration, data: D): R = visitElement(declaration, data)
+    fun visitBlock(block: JKBlock, data: D): R = visitElement(block, data)
 }

j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKVisitorVoid.kt

@@ -13,4 +13,6 @@ interface JKVisitorVoid : JKVisitor<Unit, Nothing?> {
     override fun visitLoop(loop: JKLoop, data: Nothing?) = visitLoop(loop)
     fun visitDeclaration(declaration: JKDeclaration) = visitElement(declaration, null)
     override fun visitDeclaration(declaration: JKDeclaration, data: Nothing?) = visitDeclaration(declaration)
+    fun visitBlock(block: JKBlock) = visitElement(block, null)
+    override fun visitBlock(block: JKBlock, data: Nothing?) = visitBlock(block)
 }

j2k/newSrc/org/jetbrains/kotlin/j2k/tree/jk.kt

@@ -34,3 +34,5 @@ interface JKStatement : JKElement
 interface JKLoop : JKStatement
 
 interface JKDeclaration : JKElement
+
+interface JKBlock : JKElement