FIR: optimize converting string expressions in raw FIR builder

Do get ASTNode for every string template entry as it is expensive operation

compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt

@@ -1449,9 +1449,21 @@ class RawFirBuilder(
             generateConstantExpressionByLiteral(expression)
 
         override fun visitStringTemplateExpression(expression: KtStringTemplateExpression, data: Unit): FirElement {
-            return expression.entries.toInterpolatingCall(expression) {
-                (this as KtStringTemplateEntryWithExpression).expression.toFirExpression(it)
-            }
+            return expression.entries.toInterpolatingCall(
+                expression,
+                getElementType = { element ->
+                    when (element) {
+                        is KtLiteralStringTemplateEntry -> KtNodeTypes.LITERAL_STRING_TEMPLATE_ENTRY
+                        is KtEscapeStringTemplateEntry -> KtNodeTypes.ESCAPE_STRING_TEMPLATE_ENTRY
+                        is KtSimpleNameStringTemplateEntry -> KtNodeTypes.SHORT_STRING_TEMPLATE_ENTRY
+                        is KtBlockStringTemplateEntry -> KtNodeTypes.LONG_STRING_TEMPLATE_ENTRY
+                        else -> error("invalid node type $element")
+                    }
+                },
+                convertTemplateEntry = {
+                    (this as KtStringTemplateEntryWithExpression).expression.toFirExpression(it)
+                },
+            )
         }
 
         override fun visitReturnExpression(expression: KtReturnExpression, data: Unit): FirElement {

compiler/fir/raw-fir/raw-fir.common/src/org/jetbrains/kotlin/fir/builder/BaseFirBuilder.kt

@@ -325,6 +325,7 @@ abstract class BaseFirBuilder<T>(val baseSession: FirSession, val context: Conte
 
     fun Array<out T?>.toInterpolatingCall(
         base: T,
+        getElementType: (T) -> IElementType = { it.elementType },
         convertTemplateEntry: T?.(String) -> FirExpression
     ): FirExpression {
         return buildStringConcatenationCall {
@@ -333,7 +334,7 @@ abstract class BaseFirBuilder<T>(val baseSession: FirSession, val context: Conte
             argumentList = buildArgumentList {
                 L@ for (entry in this@toInterpolatingCall) {
                     if (entry == null) continue
-                    arguments += when (entry.elementType) {
+                    arguments += when (getElementType(entry)) {
                         OPEN_QUOTE, CLOSING_QUOTE -> continue@L
                         LITERAL_STRING_TEMPLATE_ENTRY -> {
                             sb.append(entry.asText)