[FIR/IR generator] Reduce duplication when printing curly-braced blocks

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/AbstractVisitorPrinter.kt

@@ -146,8 +146,7 @@ abstract class AbstractVisitorPrinter<Element : AbstractElement<Element, Field>,
                 print(" : ", it.render(), it.inheritanceClauseParenthesis())
             }
             print(visitorTypeParameters.multipleUpperBoundsList())
-            println(" {")
-            withIndent {
+            printBlock {
                 printAdditionalMethods()
                 for (element in elements) {
                     if (element.isRootElement && visitSuperTypeByDefault) continue
@@ -155,7 +154,6 @@ abstract class AbstractVisitorPrinter<Element : AbstractElement<Element, Field>,
                     printMethodsForElement(element)
                 }
             }
-            println("}")
         }
     }
 }

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/AbstractVisitorVoidPrinter.kt

@@ -6,8 +6,8 @@
 package org.jetbrains.kotlin.generators.tree
 
 import org.jetbrains.kotlin.descriptors.Modality
+import org.jetbrains.kotlin.generators.tree.printer.printBlock
 import org.jetbrains.kotlin.utils.SmartPrinter
-import org.jetbrains.kotlin.utils.withIndent
 
 abstract class AbstractVisitorVoidPrinter<Element, Field>(
     printer: SmartPrinter,
@@ -50,13 +50,11 @@ abstract class AbstractVisitorVoidPrinter<Element, Field>(
         )
 
         fun SmartPrinter.printBody(parentInVisitor: Element?) {
-            println(" {")
-            if (parentInVisitor != null) {
-                withIndent {
+            printBlock {
+                if (parentInVisitor != null) {
                     println(parentInVisitor.visitFunctionName, "(", element.visitorParameterName, ")")
                 }
             }
-            println("}")
         }
 
         printer.run {

generators/tree-generator-common/src/org/jetbrains/kotlin/generators/tree/printer/printUtils.kt

@@ -161,6 +161,41 @@ fun SmartPrinter.printFunctionDeclaration(
     print(typeParameters.multipleUpperBoundsList())
 }
 
+context(ImportCollector)
+inline fun SmartPrinter.printFunctionWithBlockBody(
+    name: String,
+    parameters: List<FunctionParameter>,
+    returnType: TypeRef,
+    typeParameters: List<TypeVariable> = emptyList(),
+    extensionReceiver: TypeRef? = null,
+    visibility: Visibility = Visibility.PUBLIC,
+    modality: Modality? = null,
+    override: Boolean = false,
+    isInline: Boolean = false,
+    allParametersOnSeparateLines: Boolean = false,
+    blockBody: () -> Unit,
+) {
+    printFunctionDeclaration(
+        name,
+        parameters,
+        returnType,
+        typeParameters,
+        extensionReceiver,
+        visibility,
+        modality,
+        override,
+        isInline,
+        allParametersOnSeparateLines,
+    )
+    printBlock(blockBody)
+}
+
+inline fun SmartPrinter.printBlock(body: () -> Unit) {
+    println(" {")
+    withIndent(body)
+    println("}")
+}
+
 private val dataTP = TypeVariable("D")
 private val dataParameter = FunctionParameter("data", dataTP)